Ksarul

A lot of homebrew cartridge images are tailored to run on the 512K Red Boards. It has been a while since there have been any changes to it (the last one added the capability to use W29C040 and BQ4015Y chips at Rasmus' request a few years ago). Fast forward a bit, as I recently added two new jumpers to the Red Boards to add support for MBM27C4000 chip. Some of the boards used in the Realms of Antiquity cartridge are ready to use it, and are the first examples of this board revision in the wild. Why did I do this? A while back, I acquired a large quantity of non-JEDEC 512Kx8 Fujitsu chips (MBM27C4000), that weren't in the programmer libraries for pretty much any programmer with a reasonable price (anything under 1K). There is a JEDEC chip that is very close to it (MBM27C4001) though, and that one does show up a lot more often. I sussed out the differences between the two chips, and it came down to two pins being different, so I decided to build an adapter to try and program them as 4001s. My initial tests failed--the algorithms for the MBM27C4001 in the TL866 seem to be incorrect to actually program one of them--a problem I've sometimes encountered with other low-price solutions when trying to program uncommon chips. The algorithms for the uncommon chips aren't nearly as well-tested as the common ones are. I then moved up the scale to my BK Precision 844USB programmer. With the adapter properly inserted, it quickly accepted the chips once I deselected the Chip ID box. It blank checked and programmed one of the chips on the first try--and the programmed chip worked flawlessly in the newest Red Boards, so I can now successfully program the MBM27C4000 chips and use them. I suspect I won't be needing any PDIP 512Kx8 chips for a long time now. I have yet to test my rough adapter with the other four programmers I have to see how they do, but I plan to do so as time allows and will post the results here. It may be that no one else will ever need to program these, as the chips aren't common--but because of the difficulty finding compatible programmers, the prices are somewhat lower than those for other 512K chips when they do show up, and our community now has a way to use them. This may also be of use to other communities looking for ways to program these, as in my researches I found several threads on various fora looking (mostly unsuccessfully) for a usable solution. I also have a completed layout for a robust, standard adapter for these which I plan on using to make a small number of EPROM adapter boards. I'll probably build some of them for others if there is interest, as I have quantities of all of the necessary parts (including high-quality ZIF sockets) on hand. It is just a matter of finding a programmer with a good MBM27C4001 algorithm. Also of interest, Fujitsu also seems to have made MBM27C2000 (256Kx8) and MBM27C1000 (128Kx8) chips which also follow the pinout differences of the MBM27C4000, making these adapters potentially suitable for programming these two additional chips as their MBM27C2001 and MBM27C1001 variants when otherwise unsupported by a programmer. One other note: only Fujitsu made these MBM27C4000 chips. A couple of other manufacturers that use the 27C4000 designation for one of their chips, but they are not the same--their pinouts are different.

Barry Boone translated ten of the Tomy Tutor games for the Geneve many years ago, and I used his method to translate a number of Tomy Pyuuta games for it a few years ago as well (all of the 8K and 16K games, so between Barry's translations and mine, 24 titles exist).

Michael Becker made a daughter board to properly implement the DMA functionality. I believe it was usable on Revision "F" and "G" cards. It isn't needed for the ASCSI cards from SNUG, as the capability is already integrated in the main design.

Isn't there an ID-Konto program too? I think I used to have a manual for it. . .

It is definitely neat--and it also includes one path to show where the rumors of a processor natively processing GPL came from. Including the microcode to do that by 1985 was part of this roadmap. . .for a 5x speed improvement to GPL and BASIC execution times. It is also interesting to see that they figured they had better have a better grapics processor with more memory/sprites per line in place by 1983. . .

Back then, TI built most equipment to MIL SPEC. One of the tests it had to survive was a drop test. . .rumor back then was 3 feet (1 meter), but the test documentation I've seen said one foot.

I got about 30 speech ROMs with it as well--so I could actually use one of them to make a mutant Speech Synthesizer to put into my original beige case. . .without sacrificing an original speech synthesizer to harvest the chip.

I just got the Diagnostic device in the mail. It is, in fact, an original TI RAM Trap made in late 1979 or early 1980, as I suspected when looking at the auction. That gives me the last missing piece to be able to recreate them (the EPROM code in usable form, assuming there's no bit rot). The circuit card it was assembled on was purpose-made by TI for the RAM Trap. The case is interesting too. The door is glued closed, and the bottom stamp space is a completely smooth, blank plate with no identification data at all. Definitely a good purchase. . .

Marc included all of the SID music he'd translated in the files he provided with the card (about 8,000 of them, IIRC). I will have to put up a SID section on my website (which is nothing more than a placeholder site at this time).

I have an order in for a batch of SID Master boards. They should arrive within the next few weeks, depending on the vagaries of trans-Pacific air shipments. . .

But it comes with two rolls of the original paper. . .that makes it priceless.

I read this one a couple of days ago. It was definitely interesting. Thanks for posting it here.

That seller has had NOS TI things up for sale for at least five years now. Mostly consoles, cartridges, and speech synthesizers. All are pulled from original cases as shipped from TI BITD. Not sure where they got them, but they started selling stuff at about the same time Zach started selling items from the Dhein's hoard.

I'll do a test on a chip and send it your way this weekend, @Vorticon. I'll include a tested 25LS2521 as well, just in case.

I did exactly that with my daily driver SAMS board while I was assembling/testing cartridge boards this weekend. I think I have the load sequence burned into my memory now, as I know exactly what to expect--and when.

Suggestion: replace the 74LS688 with a 25LS2521. They are functional equivalents and a lot more stable over time.

Considering that that bit of loading is placing a lot of data into the SAMS, it might just be a problem there, especially as the different modules loading it have no effect (double check to make sure you don't have a file that's still in V9T9 format though, as that will kill the load process too).

No adapter needed, as it looks like the chip is a standard 2764. You should be able to read it out using the EPROM burner of your personal choice (or in system using the Australian DSR reader that @atrax27407 put up a few years ago. . .).

It would be interesting to see if/how the German magazine type-in game Alien Landing would compile. Many thanks for all the great work on these, @tmop69

There are a couple of options for replacement keyboards. Sometimes NOS keyboards show up for sale on eBay, but a majority of those (in the Radio Shack packaging) are Mitsumi keyboards, which won't help much unless the keyboard is one of the other types (about 30-40 percent are other types). Some used keyboards also turn up (just watch out for the Mitsumi types). Any of the non-Mitsumi boards can be safely used in any /4A. There are also several PC-style keyboard adapters (for XT, AT, PS2 (IIRC), or USB keyboards). Recently, discussion has also focused on the possibility of building new keyboards with modern switches (but that option isn't cheap or even available yet). One or two folks have successfully rejuvenated a Mitsumi keyboard. There is an existing thread on the process here (and the FAQ may even point to it). It isn't easy--and that mylar is really easy to tear. . . I have a whole case of original keyboards that I bought about 20 years ago--but they are ALL Mitsumi boards, so I haven't been able to use them for their intended purpose.

XKCD says it all. . .but I really have no idea what the best TI code would look like. I am personally much more focused on what the code actually does and how well it performs that function. Seen from that angle, there is an awful lot of "best" code out there.

How would you set that up, Fabrice? It would work fantastic as a selection on the boot screen to switch between the 9958 and the 9918A/29A.

Bad sockets are eeeeevvvviiiiillllll!

So it seems you've become the kilo collector, Michael. I can send you a few of mine too if you like. . .105 is just a few too many.

Now that iiiis scary. . .you must have forgotten to set your intruder trap lines. LOLOL