Sunday, October 3, 2021

Shiner ESB, an Apple Network Server prototype, and what it did at Netscape/MCom

The Apple Network Server was, with the possible exception of the Apple Workgroup Server 95, Apple's first true server. I have a particular soft spot for the ANS because it was also my first server: an ANS 500 ran Floodgap (even before Floodgap in 1998 as stockholm.ptloma.edu and gopher.ptloma.edu) from 2000 until 2012, and stockholm is still in my collection. While Apple had the Workgroup Server line, these were merely contemporary Mac designs with value-added software or hardware options, and as such ran Mac OS. (The AWS 95 ran A/UX, Apple's SVR2 Unix-System 7 hybrid, though it could also run Mac OS — being really a rebadged, hopped-up Quadra 950 — with its custom PDS SCSI card removed.)

The ANS, however, was a real honest to goodness server with hotswappable drive bays and fans, and (its most notable feature) an award-winning lockable translucent door so you could keep the unwashed masses out of your drives but still watch the blinkenlights. If you bought the bigger model, you even got dual power supplies and additional rear bays.

Also notable about the ANS was that they weren't supposed to run Mac OS, and were never sold with it, not least of which because the classic Mac OS wasn't really up to the task of being a server. Unfortunately, while A/UX supported larger needs on the 68K-based Workgroup Servers that could run it, A/UX 3 couldn't run on Power Macs even under emulation. The plan with A/UX 4 was to use a new PowerPC-native OSF/1-based kernel and possibly to also integrate portions of IBM's AIX operating system, but this plan (along with Taligent and other doomed projects) stalled out with everything else in Apple around that period. For a time Apple even considered using Novell NetWare on PowerPC; the port actually existed, codenamed Wormhole, but its tepid reception eventually led to the release of the weird Workgroup Server 9150 which just ran Mac OS. Eventually, to get to market Apple reached for what was then the only professional-level Un*x running on the new PowerPC architecture, which was AIX itself. Three Apple Network Server models were developed but only two (the "Low End" 500 and "High End" 700) were released; the 3U rack 300 "Deep Dish" remained solely a prototype, which I'd still love to acquire if its current owner ever gets tired of it. Oddly, even though they were only ever sold as AIX machines, they were initially demonstrated running a custom version of MacOS which was never released with them (I'd love to see this release myself), further confusing potential customers who already didn't want to buy Workgroup Servers. Introduced in 1996 at a retail cost starting north of US$10,000, which didn't even include the AIX license, they were very poor sellers and the line was canned by Gil Amelio around a year later.

I got my ANS 500 barely used for the cost of some consulting work after Apple stopped supporting it; you can see some scanned Polaroids of when it was in production way back in 1998. Later, I acquired an ANS 700 which I use as a spare and was briefly in service while I diagnosed a hardware issue with the 500. More recently, however, I managed to land a Shiner HE prototype dated 1995 from a scrapper in San Rafael, California. That is the unit depicted in these pictures.

The codename "Shiner" is a brand of beer named for its town of manufacture in Texas, and was reportedly the favourite adult beverage of the 1990s Server Group Division based out of Apple's Austin offices, thus lending its name to the product. Although all of the boards within this machine are marked as EVT (engineering validation test) prototypes, they are very similar to production hardware save the labelling, and the machine itself is labelled with the unknown acronym "ESB." [drudru on lobste.rs suggests, keeping with the beer theme, that this might mean Extra Special Bitter. That makes sense!]

Appropriately, Apple Network Servers remained a significant portion of apple.com even after their commercial exit; reportedly some units were still in operation as late as 2005, well into the Xserve era and almost up to the Intel transition. However, this machine — unimaginatively named shiner — had a different path, where at its place of residence it seemed to function as a test server. The disk it came with was partially recoverable and we'll look at some goodies in a moment. Unfortunately, at some point after decommissioning it was improperly stored in a high moisture environment with the lithium PRAM battery still installed. Never do this with old Macs: the battery exploded and leaked all over the board, and when I acquired the unit it was no longer working. The door keys were also missing which required me to force the lock to get into the front bays. Despite the damage and the rough handling it's endured, the board markings and residual history nevertheless make it an interesting show-and-tell piece, so I present it here.

After the pictures we'll talk about what was on the hard disk ...

Portrait. Notice the badge doesn't say Apple Network Server like a production machine — it's just a plain Apple logo and blank where the text would go. The plastic is also not textured, although it does appear to be injection-moulded.

There are two missing trays in the front. One was the hard disk it came with that I removed for safe storage, but the other came to me empty, and was probably part of the rootvg which we'll talk about later.

Close-up on the asset stickers. This machine is marked "Property of America Online" but its best documented operation appears to be earlier (again, more later). It also has a front sticker with its hostname showing it ran AIX 4.x (the hard disk I got was AIX standard JFS) and an IP that doesn't respond to anything. Also notice consistent with the pre-production plastic that there are no icons on the keyswitch for lock, unlock or service mode.
The rear has an FCC warning sticker and, on the backplate where the model and regulatory approvals would go, the simple legend "SHINER ESB H.E."
Sadly, with the logic board drawer pulled out, you can see the damage where the battery contents dripped down. You can also see the rather alarming amount of rust, er, oxidation on the fan bay. When I got the unit there wasn't anything installed in the slots except the processor card.
That said, even if the logic board were working, it would probably be somewhat anticlimactic: the money is in the markings, not in the layout, which looks very similar to my production 500 and 700. The EVT logic board is dated 1995 and the part number 820-0744-02 suggests a second revision (the production board is 820-0744-A). On this unit and the previous picture the chips themselves have their codenames on the EVT board; on the production board they are replaced with boring functional names.
For example, HAMMERHEAD and ZAX are printed on the EVT board, but the production board has their actual roles, i.e., MEMORY CNTRL (the memory controller) and DATA PATH. The appelation "SIM" on the cache and ROM slots does not appear on the production board. Hammerhead is limited to 512MB of RAM, but this was a lot in 1997, and it could accept FPM or EDO sticks. You really wanted parity in this thing, too: if all the RAM was parity, it would use 60ns timing, but if any of the DIMMs weren't, besides disabling parity it would slow RAM access to 70ns. Parity FPM RAM in particular was expensive as hell and almost impossible to find anymore. Apple sold parity FPM DIMMs in upgrade kits at typical Apple prices.
When the logic board drawer is closed, it mates with this slot on the mezzanine board which handles interconnects with the power supply, front panel and SCSI backplane. The mezz board has its own codename "HENDY." Hendy had a lot of changes as suggested by its part number 820-0713-07 but I'm not sure what they are. On the other hand, the SCSI backplane on the other side of the panel has no codename at all and is identical to my production 700 except for the 1995 date and pre-production part number.
The processor board also has its own code name ("FIGMENT"). ANS CPU boards came with a 132MHz (base 500), 150MHz (base 700) or 176MHz PowerPC 604 or a 200MHz 604e, along with a prototype dual-CPU card which was never released. The 132MHz and 176MHz cards use a 44MHz bus but the 150MHz and 200MHz cards run at 50MHz. The single-CPU boards differ only in the processor and speed resistors and use a common daughterboard otherwise. Other than markings it appears pretty much identical to production cards and appears to have had only one revision (this one is 820-0740-01; my production cards are 820-0740-A).
In particular the debugging jumpers are still on production cards (plus-minus actual contacts, but the holes are still present), just marked differently. There is hardware information on this picture and the previous one along with a bus speed and 604 power table "LEDGEND" [sic].

So, the hard disk.

The single hard disk it came with suffered the same external oxidation as everything else, but the drive itself powered up when I connected it. So I pulled the regular trays from my 500 as a precaution, installed this single tray, booted from the "Harpoon" AIX 4.1.5 CD and tried to mount it.

The bad news is that this disk seems to be only part of a larger JFS rootvg (in AIX parlance, this refers to the collection of logical hard disks that compose the default volume group), and attempting to bring it up as a standalone volume just caused a lot of errors. I suspect the missing tray contained the other disk (and, irritatingly, /). However, although Apple sold a RAID option for the ANS, this remaining disk didn't appear to be a member of an RAID array and I was able to get a sensible image of it with dd. Its hostname? shiner.mcom.com.

Yup. This ANS was at Mosaic Communications Corporation, though by this time it would have been fully converted to Netscape Communications Corporation.

strings, grep and less will get you a long way with digital archaeology on unencrypted drives. I found lots of old and new files, but overall after piecing them together the machine's primary task was running Netscape Collabra Server v3.01 21301. This was one of the all-singing-all-dancing enterprise server solutions then in vogue and was roughly contemporary with Netscape Navigator 3.0. These screenshots were extracted from its installation instruction document.

Collabra, you will recall, attracted jwz's apparently everlasting ire by being a Netscape acquisition that somehow managed to take over Netscape instead of the other way around. LDAP, NNTP and HTTP strings are present along with symbols that anyone familiar with Mozilla source code will recognize as old-school NSPR and NSS. I found part of what appears to be its configuration file:

NetsiteRoot /home2/Collabra/drd970801
Port 4444
User root
ErrorLog /home2/Collabra/drd970801/admin-serv/logs/errors
AccessLog /home2/Collabra/drd970801/admin-serv/logs/access
PidLog /home2/Collabra/drd970801/admin-serv/logs/pid
ServerName shiner.mcom.com
Backups 10
AdminUsers /home2/Collabra/drd970801/admin-serv/config/admpw
Hosts *.mcom.com
Addresses 206.222.228.86
ONEAclDir /home2/Collabra/drd970801/adminacl
ConfFile /home2/Collabra/drd970801/admin-serv/config/cron.conf
Dir /tmp
Status on

drd970801 sounds like a developer release path. This header appears on most of the control panel files:

* PROPRIETARY SOURCE CODE OF NETSCAPE COMMUNICATIONS CORPORATION
* Copyright (c) 1997 Netscape Communications Corporation. All Rights Reserved.
* Use of this Source Code is subject to the terms of the applicable license
* agreement from Netscape Communications Corporation
* author: jules@netscape.com

This guy wrote a lot of stuff, too.

The presence of LDAP and HTTP support notwithstanding, the scattered log fragments present on the machine suggest it was mostly doing NNTP (newsgroup) duty. For example, here's the administrator logging in via the web interface:

genesis.mcom.com - - [01/Aug/1997:14:29:12 -0500] "GET / HTTP/1.0" 401 223
genesis.mcom.com - nsadmin [01/Aug/1997:14:30:48 -0500] "GET /news-shiner-119/bin/pcontrol HTTP/1.0" 200 1341
genesis.mcom.com - nsadmin [01/Aug/1997:16:07:23 -0500] "GET /news-shiner-119/bin/index HTTP/1.0" 200 343

genesis.mcom.com, by the way, turns up in this Oracle discussion (allowed is not! is planet forbidden!).

And here's somebody from loaner.mcom.com posting and reading:

4 [97/08/01 16:07.20] nnrpd(0.13570):loaner.mcom.com post ok <5rtj5n$d822020@shiner.mcom.com>
4 [97/08/01 16:07.20] nnrpd(0.13570):loaner.mcom.com post ok <5rtj5j$d822019@shiner.mcom.com>
4 [97/08/01 16:07.20] nnrpd(0.13570):loaner.mcom.com exit articles 0 groups 0
4 [97/08/01 16:07.20] nnrpd(0.13570):loaner.mcom.com posts received 55 rejected 0
4 [97/08/01 16:07.20] nnrpd(0.13570):loaner.mcom.com posts received 55 rups 0
4 [97/08/01 16:07.20] nnrpd(0.13570):loaner.mcom.com times user 569.800 system 302.310 elapsed 4535.986

In fact, a generated report of the Top 10 Hosts by Number of Articles Posted only shows loaner.mcom.com. There's a reason for this we'll discuss in a moment.

As you would expect for a machine generally occupied as a news spool, various copies at various stages of the newsgroup active file are present. They include the default (example?) groups, like acl, control, junk, test and virtual (shown here in the administration interface),

but also some slightly suspicious internal newsgroups,

mcom.url 0000000000 0000000001 y
mcom.url.bad 0000000000 0000000001 y
mcom.url.bad.bad 0000000000 0000000001 y
mcom.url.bad.bad.bad 0000000000 0000000001 y
mcom.users 0000000000 0000000001 y
mcom.users.clue-impaired 0000000000 0000000001 y
mcom.white-trash 0000000000 0000000001 y
mcom.wreck 0000000000 0000000001 y
mcom.wreck.motorcycles 0000000000 0000000001 y

and most famously

mcom.bad-attitude 0000000000 0000000001 y

as subpoenaed by Microsoft in 1998, though sadly, as the numbers imply, no articles from any of these groups are actually present on the drive. Instead, what is present is a lot of test material. Rich Salz's 1991 post "Seeking beta-testers for a new NNTP transfer system" <3632@litchi.bbn.com> exists as a test file for INN; the real on-spool posts on the disk have headers like this:

Path: shiner.mcom.com!mewing@netscape.com
From: AutoPost@shiner
Newsgroups: kstress,pstress
Subject: AutoPost: shiner:119 18491-2-5
Date: 1 Aug 1997 19:54:26 GMT
Organization: Another Netscape Collabra Server User
Lines: 2216
Message-ID: <5rteti$d82102@shiner.mcom.com>
NNTP-Posting-Host: loaner.mcom.com
Mime-Version: 1.0
Content-Type: multipart/mixed; boundary="------------36A62DDA30E4"
X-Mailer: Mozilla 2.01 (X11; I; IRIX 5.3 IP22)
X-Mozilla-Status: 0001
Xref: shiner.mcom.com kstress:34 pstress:34

This is a multi-part message in MIME format.

--------------36A62DDA30E4
Content-Type: image/jpeg
Content-Transfer-Encoding: base64
Content-Disposition: inline; filename="UsenetPast.jpg"

The posting agent is actually Netscape 2, which is interesting, from an IP22 Silicon Graphics machine (probably an SGI Indy: I was using an Indy myself in 1996 when I did an independent study block at the Salk Institute). Parenthetically, a fun hostname dredd.netscape.com turned up in a few places looking through the news spool, which seems to be the same system as dredd.mcom.com.

These newsgroups (kstress and pstress) appear to be strictly local. In fact, their very name alone indicates they were solely there for testing purposes. All the other articles on the machine are just big binary base64 blob posts, made by an mewing. There is an LDAP entry for this person (here represented in LDIF).

dn: cn=NewsHackers
objectclass: top
objectclass: groupOfUniqueNames
cn: NewsHackers
creatorsname: uid=nsadmin
createtimestamp: 19970407202758Z
uniquemember: cn=Mike Ewing
uniquemember: cn=splat poster
modifytimestamp: 19970505183057Z
modifiersname: uid=nsadmin
entrydn: cn=newshackers
parentid: 0

(They don't appear to be the system administrator, though. Here's that person's LDAP entry; no other users were obvious.)

dn: cn=Administrators
objectclass: top
objectclass: groupOfUniqueNames
cn: Administrators
creatorsname: cn=Directory Manager
createtimestamp: 19970407165907Z
modifytimestamp: 19970515174534Z
modifiersname: uid=nsadmin
uniquemember: cn=splat poster
uniquemember: cn=Gena Cunnanan
entrydn: cn=administrators
parentid: 0

mewing also appears in logs,

4 [97/08/09 04:01.02] news.daily:sending a copy of the daily report by email to mewing@netscape.com

and the Collabra junk group on this machine is actually called Mike's Junk. Assuming this isn't an oblique anatomical reference (there are a lot of binaries, after all), this person appears to have been the machine's primary user, and I thus conclude the machine's primary purpose — at least at that time — was as a test spool for the news server functionality of Collabra that this person was working on.

And that brings me to the most important question I wanted to answer: how long was this machine actually in service? The timestamps from the LDAP-LDIF entries are the earliest unambiguous dates I can find on the machine (April 4, 1997), and the most recent log entry I can find in the image is this one from September 4, 1997:

4 [97/09/04 12:46.32] indexsend:[8388] stop Thu Sep 4 12:46:32 1997

A solitary 1998 timestamp 29/Mar/1998:4:36:53 -0800 appears as an example in a help document, but that document has a 1997 copyright date, so it could just be illustrative.

That said, it's entirely possible and even probable that still more recent log entries were present on the other, missing drive. The machine had to be at Netscape through at least 1999 in order to pick up an America Online asset tag; AOL hadn't even announced it was acquiring Netscape until November 24, 1998, and the deal wasn't complete until March 17 the following year (for US$10 billion — in 2021 dollars, US$16.42b). Likewise, it wouldn't make sense for Netscape to pick up the machine as a beta test and then not do anything with it for nearly a year, unless it was a later used purchase (but that doesn't make sense either because in 1997 they would probably have just bought a production machine). It thus may have been paved over at some point, or alternatively it wasn't initially running Collabra.

After all that, and with the incomplete information at hand, best guess says this machine was at Netscape/Mosaic from 1995 or so to about 1999 where it performed at least a solidly documented several months of test work. That's not a bad run for an old beast that by then was no longer being supported by Apple at all.

Are you Mike Ewing or Gena Cunnanan, formerly of Netscape? Did I miss anything? Please post in the comments if you have any light to shed. Meanwhile, you can see some more pictures of the prototype, or just read more about the ANS, the best server Apple ever disowned.

Tuesday, September 21, 2021

A happy ending (and future) for Plua

In my previous article on Plua, a port of Lua to classic PalmOS, I mentioned I was hopeful we'd have a happy ending where there was a clean-room implementation, or better still, that the original author would get in touch with me and we could redistribute it.

Well, I'm pleased to announce that Marcio himself did get in touch (he's got a lot of fun Palm and retro projects still underway, incidentally) and graciously consented to relicense Plua2c, the "cross-compiler" portion, under the same MIT license as Lua itself. You can now download the source code from Github, which I'll keep maintained.

As for Plua-the-Palm-app and its various components, I will still be hosting the .prcs on Plua Revisited indefinitely, and Marcio and I have been discussing how we can add some improvements such as expanded screen size support and the like. This means Plua has a future again, and I couldn't be happier. Thanks, Marcio!

Thursday, September 16, 2021

RIP Sir Clive Sinclair

In the US the name Sinclair is more associated with gas stations and partisan media outlets than computers. We had only the Timex Sinclair series States-side, of which the major models were the T/S 1000, a rebadged ZX-81, and the 2068, which was an upgraded but partially incompatible ZX Spectrum. (There was also the T/S 1500, a more upmarket version of the T/S 1000 roughly analogous to calling the Cimmaron by Cadillac a more upmarket Cavalier, and two minor non-American spinoffs of the T/S 2068, the TC2068 and UK2068.) These sold quite poorly in the United States because of the dominant position of the obviously superior Commodore 64 (I'm bracing for the comments from Martin), despite at least one retailer selling T/S 1000s at firesale prices so customers could get a rebate on a Commodore purchase. (Commodore reportedly used some of them for doorstops.) In the UK and Europe, however, they were a hit because they were cheap, and they introduced a generation to computers that may not have been able to afford them otherwise. My T/S 1000's keyboard has crapped out and I'm not even sure where my 2068 is, but on the announcement of Sir Clive Sinclair's death from cancer at 81, hats off, gentlemen, and godspeed.

Thursday, September 9, 2021

The Incredible KIMplement 0.2b: a KIM-1 emulator for the Commodore 64 (and the Superkim)

As I manage to eke out a little more time now for personal projects, since TenFourFox is coming to a close and the OpenPOWER JIT is developing at record pace, it's time to dust off some older items I've really neglected. This last week I started by updating the Incredible KIMplement, my MOS/Commodore KIM-1 emulator for the Commodore 64.

No, that's not a joke. The KIMplement runs real KIM-1 code using a software 6502 core I've christened "6o6" (6502-on-6502). 6o6 implements protected memory, exception handling and all legal NMOS instructions. In addition, the KIMplement not only emulates those famous six seven-segment LEDs and the hex keypad, but also is one of the few KIM-1 emulators that emulates a TTY connection (an old-school ASR-33) and a KIM-4 expander with 16K of RAM, allowing you to run "big programs" too.

The KIM-1 is one of the earliest single-board computers, at least in the sense we conceive of them today. It was introduced in 1976 as an enticement for engineers to play with the MOS Technology 6502 which was then the cheapest microprocessor on the market. MOS had just gotten its pants sued off by Motorola, who did not like the prospect of an inexpensive drop-in replacement for their 6800 CPU; the MOS 6501 was completely pin- and bus-compatible, and where the 6800 cost $179 the 6501 was priced at just $25. The "lawsuit compatible" 6502 was just as cheap, but because the pins had been rearranged, couldn't be substituted without additional design work. The KIM-1 provided a platform for engineers to become more accustomed with the 6502, featuring a 1MHz CPU, 1K of RAM, cardedge I/O, a keypad, LEDs and in-ROM support for teletypes, punch tape and cassette tape, for only $245.

MOS expected this would be a low-volume item mostly of interest to circuit designers. Instead, hobbyists bought them in large numbers because it was easily the least expensive microcomputer you could purchase at the time. With a KIM-1 at its center, you could have a full system with teletype, power supply and cassette storage for around $500. No other system came close to competing on cost. When Commodore Business Machines bought the ailing MOS in 1977, they wisely kept producing the KIM-1 until 1979 even after the introduction of the PET. Several clone systems exist, most notably including the Synertek VIM-1/SYM-1, as well as one unusual clone I'll talk about in a moment. I am the proud owner of four KIMs (including an original pre-Commodore KIM-1) and they all work.

I don't know if KIMplement's CPU core could be truly considered "virtualizing" the 6502, but it's more than just a naïve emulation. Rather than manually setting results and flags, the core looks at the guest instruction and runs the same instruction (or a safe variant) in the core context so that all the side effects, in particular changes to the status register, occur "for free." There is no way that a Commodore 64 at 1.0225MHz (or, worse, 0.978MHz for PAL) can do full-speed emulation of a KIM-1 running at 1MHz, but because there is much less code running per instruction, I think this scheme is probably near the fastest way a 6502 can run "untrusted" 6502 code. In practice it is about 35-50 times slower than native code, and this upsets programs that use tight timing or cycle counts, but it's still absolutely enough to actually "do things."

What sorts of things? Besides a couple LED-based games (originally Jim Butterfield's version of Lunar Lander, and I also added the misère game variant Black Match) and toy applications, you can run Tom Pittman's Tiny BASIC in the TTY, and with the bug fixes in 0.2b now you can successfully run FOCAL-65:

This screenshot in VICE shows the emulated 64 running a full FOCAL-65 program to manually compute square roots using Newton's method. It takes it a few seconds to do each iteration, but it all works. This is also a good demonstration of the FOCAL programming language itself including its unusual "floating point" line numbers (actually module and line), which it inherited from its more complex ancestor JOSS.

For this version of the emulator (0.2b), I finally finished some performance improvements to the CPU core that had been gestating in my mind for literally years -- the last version of the KIMplement was released in 2006! -- and also fixed a problem with the TTY emulation where typing characters could get out of sync under CPU load. It can still drop keystrokes if you overflow the Kernal keyboard buffer, but it's a lot smoother generally. I also worked around a bug in VICE where, if you try to load files from a directory on the host machine, the RENAME-the-file-to-itself test used to check for the file's presence doesn't work (a real 1541 would respond with error 63 FILE EXISTS but VICE says 0 OK).

The other bug I fixed was caused by the CPU core, but can't be fixed in it. The 6502 has a decimal flag which can be set in the status register and causes add and subtract instructions to operate in binary coded decimal (e.g., $90 - $01 normally is $8F, but in BCD mode it's $89). Famously, or perhaps infamously, the Commodore 64 Kernal IRQ doesn't turn off the decimal flag, and there is at least one SBC in the normal execution path. Because 6o6 executes instructions for their side effects, if a program had previously set the decimal flag (and this is not at all uncommon in KIM-1 code) it needs to be on for those math operations. The usual solution is to turn on the interrupt flag first with SEI to suppress IRQs while decimal mode is on, but the normal state of guest code is to have the interrupt flag clear because the KIM-1 doesn't have this problem. If an IRQ hits right that moment, the IRQ will be executed with the decimal flag on, and possible unexpected behaviour could result.

This is an extremely infrequent occurrence, but in a long-running system "infrequent" is a synonym for "inevitable." This can't be efficiently solved in the core because there is no atomic method for controlling two flags at once. A better solution is very simple: we just make a patched IRQ that clears the decimal flag explicitly, and calls the normal Kernal IRQ. I did the same for NMIs as a belt-and-suspenders approach.

The eventual goal is to open-source the KIMplement, and in particular 6o6, but I want to have another demonstration application for 6o6 as well before I do. A small multitasking general-purpose kernel sounds like an ideal way to show off how it works.

On my main KIM-1 site I also put in a few words about the microproducts Superkim. This 1979 variant of the KIM-1 was developed in Redondo Beach by Paul Lamar, who had been using KIM-1s for automotive performance testing but was unsatisfied with their expansion capacity. Unlike the hobbyist audience of the KIM-1, the Superkim is all business. The unit in my possession was clearly in a card cage; the hex keypad was never even fitted. It uses a custom board rather than a modified KIM-1 with sockets for RAM, ROM and up to four 6522 VIAs (this unit has 4K of static RAM and a Rockwell R6502P), and sports a full prototyping breadboard on-unit. But its most noticeable (and, I might add, intimidating) characteristic is the 200 gold wirewrap pins penetrating the board:
I have no idea what the sam heck this board was doing, but it clearly did something major in whatever its application was. Don't ask me to power this thing up because I'm worried I'll short something out somewhere. I don't know how many of these were ever sold and Commodore and MOS seem to have had nothing to do with its development.
Of the clones I find the Superkim the most interesting. While many people mention the Rockwell AIM-65 as a clone (my unit is above), and it is strongly based internally on the KIM-1, its substantial expansion (wide alphanumeric LED screen, full keyboard, printer) would not make it generally recognizeable as such. I think the Synertek VIM-1/SYM-1 are more characteristic, though that is one unit I don't personally possess.

In the future, and hopefully that future isn't in another 15 years, I want to add actual cassette support (right now you just dump memory to and from disk) and maybe support for one of the hi-res video boards like the Visable. It may also be worth trying to port the KIMplement to a faster 6502-based system like the Commodore Plus/4 or the Commodore 128 in 80-column mode, or maybe even the Apple IIgs, though all of these would need a solution for the sprites I currently use for the LEDs. (Okay, you Atari freaks, I know, I know.) The KIM-1 is a great little machine and surprisingly capable. The fact all of mine have survived over four decades proves they don't make them like they used to.

You can download a .d64 or .sdas of the Incredible KIMplement and its demo applications, or read more about the KIM-1.

Monday, August 30, 2021

More Tomy Tutor homebrew

Even the more obscure machines have their homebrews, and for the Tomy Tutor, I'm not just talking about third-pary tapes (though those are a thing too). In addition to 2018's Team Europe bounty (two multicarts and a reproduced "Game Adaptor" for those cartridges requiring additional addressing lines), a couple gamepads wired for the Tomy Tutor turned up on eBay. They are available in singles and doubles to replace either the Joy Stick or the Joy Controllers. Since the Tutor uses a unique pinout, these must indeed be made specifically for it; they all work fine with the Pyūta as well. (Not affiliated, just satisfied.)

Monday, August 23, 2021

The Commodore Plus/4, 3-Plus-1 and computer literacy

I'm testing lots of units in storage, including a whole mess of Commodore 264-series machines, mostly C16s (in both the domestic U.S. and Mexican Sigma variants, which are exactly the same internally), but also a couple of Plus/4s. The Plus/4 was beaten up in the United States press as the "Minus/60" because of TED's deficiencies (more colours but no sprites and worse sound) and its intentional incompatibility with the Commodore 64's large software library. Indeed, that's probably why my family upgraded to the 128 instead and completely skipped it.

Another aspect of the +4 that was mercilessly derided was the 3-Plus-1 pack-in software. Based on an integrated suite called Trilogy by Pacific Tri-Micro, it included a word processor, database and spreadsheet; the fact they were intended to be basic applications did not prevent critical displeasure. Popular Computing Weekly pointed out how small the working space was and their limited features, and InfoWorld complained that "[t]he word processor is the worst I've ever seen," but The Transactor's editor Richard Evers was particularly barbed, famously observing that "[t]he word processor is barely that, the data base [sic] defiles the name and the spreadsheet has little spread." But while this quote got wide currency, the rest of the article is actually far more complimentary, adding, "Each package is well written, taking into consideration the limitation of trying to make them all work within the confines of each other. Running two packages in tandem is possible with this system ... think of the software as an almost free bonus, and accept its limitations."

I certainly thought so. While I didn't pick up my first +4 until I was a starving medical student, it was a cheap thrift store purchase and I made good use of the spreadsheet as a household budget. The word processor was just good enough for letters (school papers I typed in Pocket Writer on the 128D, until I got a Macintosh IIsi) and I barely used the database at all, but the spreadsheet actually worked fairly well for basic figures. Best of all, it loaded instantly because everything was in ROM, and you really could switch back and forth from one to the other and exchange data without losing anything, neither of which was true of the programs I had on the 128. In some respects it was even more "integrated" than bigger integrated packages (think Lotus Symphony, etc.) on the PCs of the time. It is debatable how useful this feature would have been versus simply having the applications run one at a time for a larger workspace, but it did work.

Something else that worked was this Plus/4 that I dredged out of storage to test. While checking the contents, I found it had this letter in the box which I don't even remember noticing before:

The previous owner, in August 1986 (granted about a year and change after the +4 had flamed out), was invited to a computer literacy class, "an introduction to computers, teaching you basic data entry terminology, to help you feel confident working with computers. You will recieve [sic] a Commodore Plus 4 [sic] computer that adapts to your television for passing the class." The class was administered in Oregon.

There is no mention of any peripherals being included, and no Commodore could directly connect to a standard cassette deck for storage. Furthermore, it is likely the Plus/4 was selected solely because they got donated stock that didn't sell. Still, here was a computer that was cheap enough to just give somebody and connect up to their television. You pressed a key and almost instantaneously you got a word processor, a spreadsheet and a database that came built-in. You could type letters, do a household budget and maintain an address book. If you picked up a 1541 disk drive, which by then was selling for under $200, you could save files. If you picked up any of the cheap Commodore 1525-compatible printers on the market, you could print letters. If you cared to crack out the manual, you could learn to write your own programs.

For this person in western Oregon, this Plus/4, as idiosyncratic and artificially limited as it was, may have been their gateway to computer literacy — and at that time it very likely was all the computer they actually needed.

Thursday, August 19, 2021

Plua revisited: Lua for PalmOS (and resurrecting plua2c)

I was not an early adopter of Palm PDAs, but my experience with handheld computers is actually rather longer; my first handheld was a Tandy Pocket Computer PC-4. It had 544 free bytes (1,568 with the 1K expansion pack) and you programmed it in BASIC. Other than the TI-85 in college my next step up from there was an HP 95LX, which was the first of Hewlett-Packard's well-regarded handheld DOS machines. But Palm was the rage in the mid-to-late-1990s when I was in medical school, and I picked up a brand-new colour m505 in 2001. From there I upgraded to the Zire 72 in 2005, which I kept using until the iPhone 3GS arrived because it had better apps and it could record video. Later on I got a used AlphaSmart dana, which is the closest thing to a PalmOS laptop; it had a wide screen, full keyboard, built-in word processor, a WiFi option, two SD/SDIO slots, and USB to connect it to a printer or to have the unit act as a keyboard for a PC or Mac. Just connect it to the computer, start your favourite word processor app, and the dana would "type" your entire document into the larger computer. No drivers necessary! Although I have a few other Palm units in my collection, including an original Palm 1000, a Tungsten T|X and a couple Centro phones, plus a Pre 2 and Veer from the webOS days, I still use my Zire 72 and Dana now and then for specific tasks.

The classic Palm OS (also known as Garnet in its final revisions), not to be confused with Palm's later and technologically unrelated webOS, actually feels a lot like classic MacOS. (The "Classic" mode in webOS 1.x for running Garnet apps doesn't seem like a coincidence to me, either.) Besides the common original architecture (68K), the heavy reliance on structured resources for both applications and data storage is very reminiscent of the Mac. When ARM-based Palm OS 5 devices emerged, not only was there a 68K emulator like the Power Mac's for running older software (called PACE, the Palm Application Compatibility Environment), but the normal state of the system was to be running 68K code.

I got a lot of wear out of pre-programmed Palm apps but I'm a nerd at heart, and I like to program things. The PC-4 was easy: it was BASIC, and it had 10 segmented program spaces, so I wrote simple games and tools for school classes. The 95LX ran DOS programs, and would happily run anything I wrote in Turbo Pascal 5.5 (though optimally if formatted for the smaller screen first). However, Palm development was primarily proprietary at the time, officially requiring CodeWarrior with specific Palm support and the appropriate hardware. I used Macs (at the time, a hand-me-down Power Mac 7300), so the hardware was no problem, but I was a starving student back then and CodeWarrior wasn't cheap.

So late in 2001 it was a real boon to discover a beta Palm OS 3.1 port of the Lua programming language to Palm OS, written by Marcio Migueletto de Andrade. The part I liked best (well, other than the fact it was free!) was it was fully self-hosted, with what today we would recognize as a simple IDE, such that you could develop right on the device. In those days Plua was based on Lua 4 and offered easy graphics, serial and UI support, so I used it for writing my own internal calculation apps which (thanks to an external separate runtime, the Palm's ubiquitous IR beaming, and everyone having a Palm device) everyone on the clinical team ended up using. Eventually Plua evolved into a full-fledged 1.0 release in 2003 instead of a time-limited beta.

Plua also included a small "cross-compiler" (really, a bytecode dumper) based on luac, though with additional code to link resources as well as emit a stub PRC header to call the runtime. This allowed you to develop on a desktop PC and build the PRC there, and then HotSync it over. More about that in a moment.

Plua was already pretty great by then, but what really moved it forward was support for TCP networking in Plua 1.1. Unfortunately, networking in Plua 1.1 had several significant bugs and Marcio was already working on Plua 2.0, which was based on Lua 5, so these weren't fixed. (One of my early apps that got bitten by this was Port-A-Goph, a gopher client for Palm OS. I got a mention in Wired and the code really did exist, but the socket bugs were difficult to work around. I probably have the source code around here somewhere.) Plua 2.0 also required Palm OS 3.5 and wasn't source compatible with Plua 1.1; the functions were similar, and many function calls could be rectified with text search-and-replace, but it still had some important differences plus the jump in the core language as well. For me personally it took awhile to convert over, but Plua 2.0 was a definite improvement and the bugfixes made it a very solid package.

This screenshot, of POSE (Palm OS Emulator 3.5) running under Mac OS 9 (emulating the emulator on my Raptor Talos II), shows that Plua 2 was perfectly capable of native controls and a standard application UI. With the socket issues resolved, networking was actually stupidly easy.

At the time I was an active participant in the Yahoo! Group for Plua (now gone, along with the rest of Yahoo! Groups), which was the only official place to get Plua 2. Marcio issued an analogous "cross-compiler" for Plua 2 called, analogously, plua2c, using 5.0.3's luac as the base. However, Plua was freeware but (Lua 5 is MIT-licensed) not open source, and the plua2c binaries — which, unlike Plua 1.0 and 1.1, were distributed separately — were only available for Windows and x86 Linux.

During the Plua 2.0 betas in 2006, I privately asked Marcio if I could build a PowerPC Mac OS X-compatible version of plua2c. He agreed to this with the condition that the source be kept private (I suspect, but do not know, that he had some interest in making it a commercial product or having a commercial support option). I agreed and over the next couple years ended up issuing four binary-only releases of the Mac OS X plua2c which I hosted on Floodgap. However, after Plua 2.0 left beta around 2008, although Marcio indicated he had interest in starting on a 2.1 based on Lua 5.1, I don't know if he ever actually did; the introduction of webOS in 2009 and the lack of interest in Palm OS Cobalt or further Garnet devices essentially ended classic Palm OS's market relevance in any case. I lost contact with Marcio and never received further replies from him regarding Plua or plua2c.

Still, I kept using it for various minor projects even if I didn't regularly keep a Palm in my pocket anymore. I eventually gave up on Port-A-Goph and started on a Plua 2 rewrite (the screenshot above), and turned my Zire 72 into a Plua-powered Hue light controller:

All of this development was done on my 32-bit Power Macs, using 32-bit builds, which was all that was ever supported. In the meantime, the Plua Yahoo! Group disappeared along with the rest of everything in the Yahoo! Groups genocide and along with it the only definitive source of Plua and plua2c. Although a few people have the PRCs, no one seems to have kept the cross-compiler, and other things like documentation and examples similarly evaporated.

When I recently decided to continue work using my Raptor Talos II, which is a 64-bit POWER9, I decided I would dust off the source code of plua2c still sitting in my G5 and develop on the new machine. plua2c compiled and appeared to function but ended up generating defective executables that weren't compatible with the Plua runtime (Plua2RT). They were dramatically bloated in size and caused the runtime to emit a low-level VM error.

Recall that plua2c is descended from luac, which more or less just dumps the Lua data structures in place. Lua's documentation says that "[t]he binary files created by luac are portable to all architectures with the same word size." To this end, luac 5.0.3 actually emits sizeof(int), sizeof(size_t) and sizeof(Instruction) (i.e., the typedef quantity for the size of individual bytecode instructions) into the bytecode header which should make an amphibious loader capable of selecting different bit widths, but Plua2RT doesn't swing both ways, at least not in that respect. To make the Plua VM happy, I had to force all of these to be 32 bits in size and change the emitter to only emit 4-byte int and size_t quantities.

This partially fixed the size, but it was still abnormally enlarged, suggesting 8-byte quantities were still being injected into the file somewhere else. After some detective work I found it was actually coming from plua2c's PDB header struct, so I hardcoded the correctly sized types in its typedefs, and the length matched up and the Plua VM could now execute the generated PRC. plua2c was now ported to 64-bit OpenPOWER.

You'll notice I said the length matched what my Power Macs emitted, but not the file itself. Besides a timestamp, the Lua bytecode is emitted using the native system's endianness, and the dump also has an endianness flag to indicate what that was. Interestingly, this is one situation in which the Plua VM does swing both ways: although the native endianness of the 68K Palm OS is big, and Plua was never ARM-native (which for Palm OS 5 is little, and PACE handles the endianness switch as part of thunking), it transparently converts the values just fine, just like Lua would. The docs even say, "binary files created on a 32-bit platform (such as Intel) can be read without change in another 32-bit platform (such as Sparc [sic]), even if the byte order ('endianness') is different." In fact, it has to, because Marcio's builds of plua2c were for little-endian 32-bit x86. Only my PowerPC Mac OS X builds actually emitted big-endian data, since that was the native endianness there. My POWER9 system runs Fedora in little-endian, so the endianness didn't match the Power Macs, but that was no problem for Plua.

I intend to honour my gentleman's agreement with Marcio about not disclosing the source code. Even if he's unable or unwilling to discuss changing the arrangement, a deal is a deal and I would want this to be a sign to anyone else who would share code with me for porting purposes that I keep my promises even a decade and a half after the fact. Still, I think Plua is a great way for retrocomputing enthusiasts to get back into Palm development. Yes, there are tools like OnboardC which compile on the Palm as well, and some but not all of the C cross-compiler infrastructure works on modern 64-bit systems, but Plua is a lot more straightforward for beginners and has tons of built-in functionality that would require external libraries or a lot of additional code with other development systems. The use of a separate runtime is a little obnoxious but hardly a dealbreaker for me personally.

So, in the spirit of our original arrangement to issue PowerPC Mac OS X binaries, I have compiled plua2c for modern 64-bit platforms, at least the ones I have a compiler or cross-compiler for. Besides the 32-bit PowerPC OS X version, which I still offer, and the 64-bit OpenPOWER ppc64le Linux binary I personally use, I also compiled it for Intel macOS 10.14+ with clang and 64-bit Intel Windows with a cross-compiling MinGW gcc. I'm willing to consider other platforms if I can easily set up compilation without a lot of additional work or disk space.

But these aren't much good without Plua itself, so I've additionally started hosting the Palm OS package on Floodgap with the runtime, onboard IDE and online help, along with Marcio's documentation and license terms. I also had a complete copy of the Plua 2 examples, so I've provided those, like the animated fishtank you saw on the introductory image. And, because building them from scratch needs the PILot Resource Compiler, I also made a minor 64-bit fix to its bitmap handling for modern systems too (it's GPL, so for that you get the full source code). Fortunately, pilot-link is still readily available for most modern platforms to sync your binaries over to the device.

It is my hope that one of two things will happen: Marcio will get in touch and bless an open-source release, or, with this tool, someone(tm) can work on a clean-room implementation of the runtime and maybe fix a few of the issues like memory usage and custom screen sizes. Sadly, that someone(tm) can't be me, because I've obviously seen the source code and know at least some of how it's implemented and that makes me a tainted implementor. But combined with the source for Lua 5.0.3 — and none of what I've divulged here can't be inferred from it — folks should be able to tease apart how the VM is constructed and how calls get to the OS, because except for the Palm-specific bits the VM core is still regular old Lua. Which is why, by the way, Plua was so great and is worth resurrecting. Maybe we could even get later releases of Lua 5 working. Who knows?

Even if we don't get either of those outcomes, at least now folks interested in Palm OS have another solid homebrew development option available once again. I got a lot of wear out of Plua and Marcio's hard work is why. I don't think he ever made a cent off it, but even with its minor warts it's still my favourite way to program the classic Palm OS. Now you can enjoy it too.

The binaries, documentation and examples are at Floodgap. As for the gopher client you saw? Well, that's a future post. But when I push that out, you can compile it yourself.