After a long gap, here's the last (or possibly penultimate) part of the 1200XL upgrade story. In the last part (well over a year ago), I'd fitted VBXE and Stereo Pokey, and finished the PBI and power mods. Since then I've added Ultimate 1MB and one of Dropcheck's excellent GTIA PAL adapters. This means that the 1200XL is completely "PAL" in the very strictest sense. Legacy video output now works on my 1084S monitors, and for hard disk storage I've been using Ultimate 1MB/SIDE (in PBI mode), and
Welcome to another thrilling installment of my 1200XL's story. Prior to fitting the Ultimate 1MB board when it arrives, I decided to install the Mega-HZ stereo board. Unfortunately, I'd neglected to request turned pins from Wolfram, so I decided to replace the square header pins on the stereo PCB myself. I have no problem with the square pins as such, but I wanted to resocket the 1200XL with precision sockets and I didn't want to leave a machine socket under Pokey. The square pins do tend to wea
Welcome to the final installment in the saga of the "Poor Man's 1400XL"! After rectifying some problems with the VBXE board, we're now all set to finish the PBI and realize perhaps the nicest Atari 8-bit imaginable...
PBI wiring wasn't quite as bulky as I'd expected, and although I wanted to leave plenty of "slack" in case I need to desolder components via the underside of the board in future, I think I could shorten lots of the wires:
Nevertheless, once I'd figured out my key mista
After a short respite (time spent finishing the SIDE driver), I'm back onto the 1200XL and pushing ahead with the PBI connector. Wiring the 50 way ribbon cable was less difficult than plain fiddly, but the tinned wires seemed magnetised to the solder cups. So - reasonably neat by my lowly standards:
It would be easy to get into knots with regard to pin numberings and signals, so I checked, double-checked and triple checked Mapping the Atari, Bob Wolley's 1200XL PBI instructions, and my
It seems I left the most important part of this mod almost till last: the PBI itself. I'm following the (amended) instructions by Bob Wooley (PBI for 1200XL), but it took me a week to find a suitable bracket for mounting the 50 way Centronics connector to the back of the motherboard. I picked up all kinds of cheap metal brackets from hardware stores, but ironically enough the suitable parts were eventually found in the spares box right here at home. I absolutely did not want to mount the connect
Centronics connector arrived from RS first thing on Monday morning, but we need to finish the VBXE installation first before figuring out a bracked for the PBI socket. Following Bob Wooley's article, we use a piggy-backed 74LS08 (although Bob recommends an HC) to create the EXTSEL line which is absent on the 1200XL. This is required not only for the PBI but for VBXE itself.
I haven't lost my "spaghetti" leanings, but at least some shink-fit insulation is in evidence.
The XL VB
On Saturday evening I had time to securely fit the sockets and wire everything up. I'd have felt more confident if I actually knew what I was doing; my knowledge of electrical circuits being nil, there was every possibility that some disastrous short or otherwise bad connection would result in the whole thing blowing up. However, dumbly following a plan and reinstating the ground-away traces with jumper wire, I ended up with two secure DIN connectors. The power connector is especially sturdy, be
Straight on with stage 2 of the project, and it's time to start drilling and cutting. No turning back now!
The DIN7 (for the new power connector) arrived this morning so I now had all the parts required to perform the basic modifications. I wanted the DIN sockets to fit properly in the board (not just sit in a pool of hot glue), so clearly it was going to be necessary to cut, remove, or re-route some traces around the power socket and switch. I took photos of the traces beforehand just to be
In light of all the excitement surrounding the recent 1400XL and 1450XLD developments and the speculative $1000 price tag for repro models, I decided my 1200XL offered me a better stab at a bit of Atari luxury. It had lain in the cupboard for most of the time since I received it (as a very generous donation from a Canadian forum member) a year or so back, and the crappy video output, the fact that my 1084S won't sync to the NTSC luma, and the lack of a PBI made the machine seem more of a decorat
Last time, I took a brief look at the history of GUIs on the Atari 8-bit, and I want to spend some more time looking at them before we move onto a detailed description of the new GUI project. Since I wrote part 1, I remembered another fledgeling GUI which was in development around the same time as Diamond: GOE (Graphical Operating Environment) by David Sullivan. This interesting package takes a slightly different approach from Diamond, but still employs the usual desktop metaphor with icons and
When Diamond GOS was released in 1988, it seemed that the Atari 8-bit finally had a GUI to compete with the Commodore 64's enviably slick and professional GEOS operating system. A very young Alan Reeve had churned out Diamond while studying Computer Science at Northern Illinois Universty. In the face of various marketing and technical problems he managed to produce a cartridge which to all intents and purposes implemented a cut-down version of the Atari ST's GEM desktop on its 8-bit predecessor.
Now that I've socketed the CPU and other custom ICs, I can fit the adapter I've constructed. The idea of this is to bring out all the CPU signals to a convenient header in order to avoid the frequent need to solder jumpers to legs of the CPU:
I wanted to use pins on the header, but since the daughterboard which will plug into the top of the adapter is also single-sided veroboard, it's easier to use sockets.
The jumpers attached to the adapter are for the 1MB SIMM upgrade. It's
Enforced stasis with various projects encouraged me to fit a stereo upgrade in my VBXE machine today and while I was about it I decided to socket (as well as POKEY) the CPU and GTIA. The OS ROM, ANTIC, MMU and various other ICs were already socketed.
Here's the IntSDX (socketed), with GTIA ready to come out:
Today's was probably the smoothest desoldering session I've yet managed. I use a 15W iron and a solder sucker. To those inexperienced: the key is patience, and not pressing down
Hooked up the XF this morning to see if there's anything of interest on the floppy disks from back in the Nineties. Here's something very much of its time: an article on SpartaDOS X I must have intended to submit to New Atari User (just as it was folding). It's rather slight (I cringe at times reading stuff I wrote way back), but there are one or two insights and the part about AMAC is something I'd forgotten entirely. For all I know, the bug still exists:
THE SPARTADOS X-FILES
by Jon
The final stage of the assembly was less time-taking than expected. Fortunately the new button mount proved extremely effective, and I'll be using the exact same method with future builds.
So, first job today was to solder up the switches and LEDs:
Once this was done, the buttons were attached to the special platform I'd made earlier:
The buttons basically run 1 through 4 from bottom to top, with the fifth button being "shift". It would be nice to have them labell
I didn't get around to blogging progress yesterday, so two days worth of updates today.
Since the LCD display needs to be rotated, I decided the cabling would be more flexible if I separated the wires and the baled them with cable ties:
Before I got hold of some LEDs, I decided to start work on the case. This is far and away the most fraught and perilous part of the job, as one wrong cut can ruin the case (XM301's are plentiful, but the supply is not inexhaustible and they're not av
I finally managed to find some of my preferred ribbon cable this morning (not so keen on the copper core stuff), so we're ready to wire to LCD back up to the PCB. If the unit still works after this stage, we're well on the way. Otherwise, we have some serious explaining to the client to do...
First job is to trim the ribbon cable. I've peeled away sixteen strands, cut them to about six inches in length, spayed the ends and stripped them. I then tin them:
Having tinned both ends of t
Although SIO2SD is a fine device, it's usually supplied as a bare PCB. Various custom cases have been made, but many SIO2SD owners use the board "as is". Mine was without a case until late 2009, when I decided to put it inside an XM301 modem housing. After two attempts, I ended up with this:
Although my conversion is still held together with tape, the project was a complete success and generated a not inconsiderable amount of admiration. My attempt at using the XM301 casing for this was
Having the program code underneath the extended banking window is proving such a headache that I've turned my attention - for now - to updating the "Shadow RAM" version of LW with some of the new features intended for the "Pro" version. Such are the changes being made to the standard version, that the Sparta 3.x compatible version will probably have to be started again from scratch (since it's built on the codebase of the current development version). In any case, I'd rather make progress with s
It's been a fraught week of hardware problems, but in between all that I've managed a few hours' coding. Moving The Last Word's code under the banked text buffer has proved more difficult than I thought: a program which was designed to access linear memory in an ad hoc fashion needs a lot of careful reorganisation to ensure target code never gets switched out at the wrong time.In prior versions of LW, the page at $7F00 has held pointers and tables pertaining to the text in the memory between $40
Rather than keep posting in the forum, I thought I'd start this blog to chart the ongoing development of The Last Word, a word processor for the Atari 8-bit which first saw publication in December 2008. Since that time, it's been adapted to use a fast and efficient software driven 80-column text display, detect and use most popular RAM upgrades automatically, and incorporate a file manager which makes maximum use of SpartaDOS X. The program has a complex macro language, and can hold up to ten fi
Having just about finished my "primary" machine, I stare at the mess of wires and think just how much I've learned over the past twelve months...This time last year, I'd never used a soldering iron before. The 128K upgrade in my original 65XE was fitted by my father in the early nineties. His eyesight was poor, his glasses thick, and he did the whole job on the dining room table with a jeweller's eyeglass strapped over the right lens of his spectacles. The first soldering job I ever did was the
So I had some time on my hands recently and the matter of 6502 assembly language came up in conversation. I hadn't written a program in nearly ten years, and the Atari was gathering dust in a box two miles away. Two weeks ago I fetched it home and have hardly left it alone since. Why do all roads lead to Atari? I've installed a Beta of Windows 7, I use OS X Leopard, yet the Atari is more fun than either. It's not necessary to write a word processor any more, but still I'm looking forward to mess
Like us on Facebook
Follow us on Twitter
AtariAge on Instagram
Watch us on YouTube
Chat on Discord