Tuesday, May 30, 2023

Refurb weekend: Commodore 128DCR

No question: the Commodore 128D is the finest Commodore 8-bit ever made. On this I tolerate no dissent, and that's not just because I sometimes hang out with Bil Herd. It's a 128, so it's got VDC graphics, 128K and 2MHz operation, but because it's a 128 it's also a 64. It's also an upgraded 128 with the fixed ROMs, (in this North American 128DCR) 8568 VDC and 64K of VDC memory, it's got a built-in 1571 (Commodore's finest 5.25" disk drive), and it doesn't have an external power brick. Plus, even though it has the desktop footprint of a 128, the detachable keyboard means you can just put a monitor on top of it (and the steel-cased North American 128DCR handles that very well) just like you can't with a flat 128, and you either get an actual cooling fan with the plastic 128D or the solder points to put one in a steel 128DCR. My only complaint is that the consolidated DCR motherboard is nearly devoid of socketed ICs, making it a little tough to do component level repair on. I like spares, so I have four DCRs, all of which completely or mostly work (and two spare keyboards, one rather yellow but fully functional and one even more yellow and useful just for parts).

This particular 128DCR has been a constant presence on my desk since the mid-1990s when I first got it as an upgrade from my ailing flat 128. But it has one flaw: it doesn't have a working CIA Time-of-Day clock, which isn't used much by software, so I never bothered to do anything about it. This was tricky when developing TOTP-C64, since the 30 second timer between emitting TOTP codes uses the TOD clock for maximum interval accuracy (the 50/60Hz Timer A interrupt that drives the TI/TI$ jiffy clock can be stalled and lose time, whereas the TOD clock is based on the AC mains frequency and thus is as accurate as your plugged-in wall clock); one of my portable SX-64 systems, my second favourite Commodore 8-bit, handled that portion of testing instead.

Well, now that I've got a new Ultimate II+L cartridge in fire-engine red with its own real-time clock (among other great features), I'd like to update TOTP-C64 to support it and I'd rather do it on the 128DCR. That means we should fix the TOD clock. And that means ... a Refurb Weekend!

Friday, May 19, 2023

The KIM-1 that sounds like Stephen Hawking (or: "jitbanging" DECtalk)

My 1976 briefcase Commodore/MOS KIM-1, a 1 MHz single-board computer with a 6502 CPU and 1K of RAM, has learned to talk — with a familiar-sounding voice.

The KIM-1's serial lines are connected to the last and smallest member of Digital Equipment Corporation's true DECtalk hardware speech synthesizers, the 1994 DECtalk Express. The DECtalk's classic default voice heard in this video is Perfect Paul, which (with adjustments) was the voice of Dr Stephen Hawking as produced with the 1988 Speech Plus CallText 5010.

The 15 keys we can read off the KIM's hexadecimal keypad are polled by a "talker" program that sends the DECtalk Express words and phrases to speak. However, although the KIM-1 has 20mA current loop output you can turn into RS-232 serial, its built-in ROM routines can't reliably communicate at the 9600 baud rate the DECtalk Express demands.

So, in today's entry, we have a veritable smorgasboard of geriatric geekery: using our KIM-1 serial uploader to push a program for execution, let's write a bitbanged 9600 baud serial transmitter routine in 6502 assembly and let the KIM-1 have its say — and crack the DECtalk Express open and look at the insides while we're at it. (Teaser: you'll find its CPU very familiar.)

Wednesday, April 26, 2023

Of Sun Ray laptops, MIPS and getting root on them

I like Sun Ray laptops. They make surprisingly useful thin clients. Here, going from right to left, I'm playing Quake on my Solaris UltraBook IIi while it serves a Sun Ray session via Sun Ray Server Software (SRSS) to my silver Sun Ray 2N in the middle, and on my Accutech Gobi on the left I'm root.
Wait, what? Root on a thin client?

Let's rewind a little.

Tuesday, April 4, 2023

Crypto Ancienne 2.2: now supported on AmigaOS and classic MacOS/MPW

As threatened we're up to the next checkpoint with Crypto Ancienne, the TLS 1.2/1.3 library we maintain for pre-C99 vintage compilers and architectures, so here's version 2.2, or "Crypto Ancienne Meets the Hooded Fang" (read about previous releases).

New checkpoints are always an opportunity for new ports. Why am I showing you a picture of my Amiga Technologies A4000T? Because AmigaOS 3.9 is one of them!

Friday, March 31, 2023

Refurb weekend: DEC AlphaPC 164LX

It's time for another Crypto Ancienne checkpoint, which will be a post Real Soon Now(tm), including some new operating system frontiers. But part of the work for Cryanc is all the build regression testing on the supported platforms: each of the platforms I vouch for has to be able to compile the updated source code and use carl, its built-in mini-curl clone (officially the "useful" demonstration application), to successfully and completely download from a selection of real websites. One of these is harlan (named for Harlan Anderson, co-founder of Digital Equipment Corporation), my one and only DEC Alpha-based machine, a DEC AlphaPC 164LX running Digital UNIX Tru64.

The DEC Alpha is a good test for Crypto Ancienne because it's a fast (for the time) and finicky (for all time) RISC architecture, with notoriously strict alignment requirements and an extremely loose memory model. Early Alpha CPUs in fact entirely lacked instructions for direct short or byte access — 32-bit, 64-bit or bust. Unfortunately the Ethernet card blew while I was testing Cryanc 2.0 and I couldn't validate that version, so I just pushed that checkpoint out the door. Well, we can't do that two releases in a row, darn it. I have a replacement NIC and a mission. It's time for a Refurb Weekend.

Tuesday, March 21, 2023

Printing real headline news on the Commodore 64 with The Newsroom's Wire Service

Besides other things I've written or supervised, so far in my time I've also edited three periodicals, and Springboard Software's The Newsroom is a big reason why. In today's article we'll not only look at the guts of this pioneering 1984 software package, but also solve a childhood mystery I've wondered about since the very first day I touched the program by MITMing an RS-232 connection to snoop on serial data — and then print out a brand new 2023 newspaper with 2023 headlines to prove we cracked the case. (Scroll to the end if you just want to see the finished product.)

Saturday, March 4, 2023

Refurb weekend: Cobalt RaQ 2

In the post on our recently resurrected fork of Dreamcast Linux, I mentioned the NetBSD NFS server providing basically all of its persistent storage. A few days into the development work I started hearing a weird whine coming from the server room and sure enough the NFS server had a bad fan — in fact, the only fan cooling the entire 1U system. That means it's time ... for another Refurb Weekend!