Ksarul

Ack! You have reminded me of a twisted poem I wrote in high school (nearly 50 years ago): Bees, Bees, In the trees, Not asking please, To bite me on the knees! The teacher wanted a four-liner in a recognizable format. He was expecting one of the standard poetry formats, but did not contemplate a nut like me who would devise their own format on the fly. He wanted to know where I found the format--and was pleasantly surprised when I told him the format was my own. I think I wrote 40-50 of them over the years, and I know of two or three others that adopted the format as well. Bats, Bats, Furry gliding rats, And uncomfortable living hats. Now I need some flying cats! And another one, written now for the fun of it. . .

I really need to modify the two bare Myarc 512K boards I have to add them to my Geneves. . .Paolo Bagnaresi spelled out the necessary changes a long time ago, I just need to take the time to actually do it.

Actually, I did some extensive tests with the UberGROM this weekend using both of the Tutankham cartridges I had on hand. I had no failures, and I had a lot of different hardware connected while doing the tests. I also used a Navarone cartridge expander for some tests just to add a small timing delay--and the cartridges still worked every time. That was why I suggested testing it with other GRAM devices, just in case that would help us isolate where the problem was showing up. I need to look at the specs to carve up a GRAM Kracker compatible image to test with (unless someone has already done that and can post it here). Omega's UberGROM copy doesn't fail either, so that is a second data point. It is a thorny compatibility problem, that's for sure.

Reading the documentation, that indicates that the issue is most likely in the ROM file, not the PCROM file. Pressing the selection key sets up the parameter pass to the ROM by placing the value in the Scratch Pad and lobs control to the ROM. It looks like the ROM is then failing to set up the game screen when it is supposed to reach back to the PCROM to grab the necessary graphics data. Something in that startup loop is off. I wonder if it has to do with the bank switching functionality? Is that initial write to select the bank overwriting something important to the rest of the program? This might explain the difference between a GRAM device failing, but a GROM device working. . .just thinking out loud here and I may be totally off base.

Hans Otten has been a p-System person almost forever--I remember seeing things from him back when I was a member of USUS. . .and stuff from you too, for that matter, @apersson850

Thank you Eric! You have made my day once more!

The software for the Wiesbaden Supermodul II parses out every single type of GRAM cartridge file that existed back then as part of its load routine (it will automatically recognize known types and load them without user intervention). It can also save them to any format it knows. Sven Dyroff published a copy of the parsing logic diagram about ten years ago (in German). I cleaned it up (the original was handwritten) but I have to verify that I still have the cleaned up version on hand as I lost some stuff that I didn't have backed up a few years ago.

I sell them directly to folks once I have them ready. I just maintin a list of those looking for them and let them know when I have some ready. Gruß, Jim

The first 500 or so bytes of the PCROM for is the GPL needed to launch the cartridge and select the number of players. This part of the code should be identical in all four PB cartridges. Launch to ROM occurs once the number of players is selected and passed to the ROM routines. The remaining 5.5K of the PCROM contains graphics and sound lists and also controls ROM bank switching--it doesn't contain anything else, based on the spec, as PB considered GPL to be too slow for program execution. The Frogger source may be helpful in looking at how PB was setting up the grabs for graphics and sound data in their code.

I knew we had the Parker Brothers development documentation somewhere (I spent much of this evening hunting my copy down). They call their GROM-like chips PCROMs (Program Counter Read Only Memory)--I forgot about the leading "P" when discussing it in the past. Here is the document, which describes exactly how it was used and how much of it was usable by the game programmer as well. It also includes the source code and some examples of how to hook to their startup code. Like GROMs, these were 6K, 16-pin chips. About 5.5K could be used for part of the program, the rest was eaten by the PCROM control program. Here's a link to an interview with the Tutankham developer. He admits that there is a single known bug--but considers it more feature than bug. Also, the source of the PCROM files also had complete, original source code for Frogger, so I included that here as well. wickstead_ti994a_PCROM_overview.pdf wickstead_assembler_d4_11-15-83_ti994a.pdf

One important thing that is obvious from the PB documentation that turned up a few years back: they did NOT have TI permission to use GROMs. Parker Brothers designed their own chips that they believed successfully got around the issue by solving the problem in a slightly different way. These chips were called CROMs (not GROMs). The world of random chips on the boards replicates their CROM address selection circuitry (a workalike to the TI GROM). TI did something similar on their EGROM cartridge boards for GROM circuitry. There isn't a dump of the original prototype anywhere, so we can't make a direct comparison of the files, unfortunately. Making a dump of it available to compare against might violate the owner's NDA, so it isn't an option. In his defense, I wouldn't want to take that particular risk either, based on what I know of the NDA. I suspect that it's likely that the builds would match if they could be compared though, as anyone else at PB who had copies back then would have had the latest builds for their testing--and those builds would have been the ones that walked out the door. It really depends on how many test builds there were before they reached final (and a copy of the debug testing records would be most informative there, although I doubt one of those will ever turn up). Something I didn't identify in my original test was that I also tested it in a cartridge expander--and there were no issues there either. I suspect there may be a subtle difference in the FinalGROM timing that makes a difference with this game, especially if the emulators aren't experiencing the same issues. It would be interesting to look at it on real iron using a Wiesbaden Supermodul, a GRAM Kracker, a GRAMulator, a Maximem, a p-GRAM, a Mechatronic GRAM Karte, and an HSGPL. Maybe something will show up in those tests that would give us a clue as to where the problem is buried. . .

I did a short test this morning just to see what would happen--the cartridge does not show up on the cartridge menu screen (I pretty much expected this). I'll have to look later to see if the cartridge-reading software properly detects the GROM to read it out (once I dig that disk out again).

UberGROM with PEB, SAMS, Myarc HFDC, HRD4000B, and homebrew speech in PEB adapter. Starts and runs fine, generally made it to the second game screen before I got killed off (a normal thing for me). I'm sending Fabrice an UberGROM board with the game loaded on it to see if that changes his symptoms. . .

I'm waiting on a lot of the boards to come in, so I should have some on-hand within the next month or so. I think I still have a dozen or so of the necessary connectors. The GERBERS aren't online, as I try to keep the boards I design permanently available to the community at reasonable prices (and based on buying in reasonable bulk lots to keep that price-per-board low). The connectors for this one weren't cheap either--and are relatively difficult to source. I "think" Sullins may still make them. . .but that's about it.

I've actually been working on a list like this for several years--but I started it on paper and I keep misplacing it. I really need to transfer the data to a computer and put it online. . .

This was the one on eBay. I already had the program disks that require it (and variants of those programs were released into the wild as part of the software dump TI sent to users groups when they left the market). The programs need the dongle to actually print to the printer types identified on the label and may be needed for other software functions. I've never loaded the disks before that, as I knew they needed the dongle to work. I do plan to read out the GROM soon.

Mine arrived today. . .fantastic work @adamantyr

True, but what we don't know for sure is that the code we have is identical to the code on that prototype. The GRAM files came from a different source, and are of unknown provenance. Bryan had to sign a never-release-the-ROM NDA in order to complete the original transaction. Maybe we need to ask him to compare the code we have with the code in his proto to verify that they are the same release. . .that way, he isn't violating his NDA, but we will know for sure if the code is correct. I think that answers your question @mizapf (we were typing at the same time). @Toucan, can you safely shed any additional light here?

Here's a link to a picture of the prototype. Bryan Ropollo bought it from the original programmer a long time ago. . .it is a very strange board, but it emulates the PB CROMs described in the CROM specifications discovered a few years ago (posted here and on WHT, IIRC).

Kyle got back to me yesterday. He is in the process of digging his WHT items out of storage to determine what he has left on hand. I also pointed him here in the hope he would join up with us.

Here's one most of you have probably never seen. It is the Security Module for the p-System Word Processor and the p-System Spreadsheet programs. It even has a GROM in it. . .

Has this one made it any further into the conversion process? I am in awe of your ability to port these games successfully.

Has there been any progress on this one? If not, you may have a broken wire in the cable between your floppy controller and the drive.

Thank you for doing the clearinghouse work on these, @acadiel

I have one I've been working on off and on, but it has been a backburner project. I need to make a couple of test boards using my laest layout to see if the changes I've made cleared the bugs in my first iteration test boards.