Geoff Oltmans

I love these types of discussions. ha I was an avid Amiga 500 user back in the late 80's/early 90's. I think midway through the 500's lifespan is the point (in the US at least) that the Amiga really gained a lot of popularity, which is not really saying much. ha. I think I recall reading that the Motorola dropped the CPU costs which helped drive down the costs of the Amiga quite about the time we got one. My parents paid about $500 for one at WaldenSoftware when it was still around. It didn't include a monitor so I was stuck with smeary composite video with the included 520 adapter on the hand-me-down composite video monitor from the TI 99/4A, then Commodore 64, then Amiga. We got a used Commodore 1084 a couple years later used but was still over $200 if memory serves. By the time you added mass storage and a 1084S monitor, you were pretty solidly into PC money territory. But, it did for a while have better video and sound capabilities at a cheaper price point. It was pretty clear to me when I saw Wing Commander running on a PC with VGA and a sound card that the Amiga's days were numbered.

Well, depending upon adjacent to what facet, my vote would be the Coleco ADAM. Oh wait, I already do that one. ha But out of your list, probably the Tutor.

Apparently, the TI disk controller uses the index hole because my attempts to make flippy disks for my single sided drive fail miserably. Heh

Never really considered that but that makes sense. I guess if the controller can't compensate by using an appropriately higher recording speed then you'd have issues there too.

I wonder if that was a real concern or not. I mean, the 99/4A is clearly not built to the standards of a business application.

The biggest problem with high density drives is that the heads are smaller and thus write smaller tracks than are meant for 40 track drives, so interoperability with 40 track drives is problematic. Reading disks is okay, but writing data back is an issue.

Right. I think they were about two years to late to be relevant.

I have to wonder what Commodore was thinking with the TED computers. At least in North America, nobody wanted them. EDIT: It was also pretty clear by that time in the US that nobody wanted that badly a cost reduced computer either with other brands and were willing to pay extra to get the much better supported Commodore 64.

With the real Windows 98 machine and real com port hardware, things have fared better. I was able to transfer the hook program at 9600 baud with a couple of attempts. Seems to be pretty reliable once I changed the configuration options to include the handshaking signal config (DTR=DTR, CTS=CTS, DCD=DCD).

I should note that I've had issues with the communication timing out occasionally between VDM99 and the TI... not sure if it doesn't like the VM or XP or both. I have a bona fide Windows 98 machine with hardware serial port that I'm going to try next.

Sorry to necro this post, but I've been trying to get this vdm99 to work for a little bit and I finally found the secret sauce that works for me. In my case I'm using a Windows XP VM in VirtualBox, serial cable USB dongle. I attempted to transfer the rs232 hook to the TI with a big fat nothing but fail using TI Extended Basic. Every combination of speeds wouldn't work. I then switched to Editor/Assembler, and loaded through TI Basic, at 300 baud, the hook program. In vdm99 I switched it back to 9600 baud and did a phony hook upload and then when it asks to poll the TI, I start the hook with CALL LINK("GO") and then hit 'yes'. Voila.

I used some contact cleaner on the power switch thinking that might be it. I’ll try with the power plug that’s a good idea.

Do 99/4As generally suffer from power up reset issues? Namely when turning on the console do they sometimes not initialize to the splash screen the first try? The console I've got now does this, a subsequent power down/up usually takes care of it and seems like my old console from many years back also did this.

Oh, and the noisy video thing. I think there may be something up with my monitor now. The other console does the same thing with predominately white displays. I guess maybe the white signal is "hotter" than my other machines maybe? I haven't checked the output levels relative to my other machines yet.

15 line display!

Update: I was able to borrow another console from a coworker and using the FinalGROM99 cartridge I have I noticed the same strange behaviors with certain games with that. I used the tests from the github repo for running on-target tests for GROM page accesses from there and found that several of those tests fail with anything plugged into the expansion port on the console, but doesn't if nothing is plugged in. In the other thread in here for the FinalGROM99 Firmware for QI consoles I installed that firmware and my problems went away! So, I have a perfectly functioning console now. Turning my attention back to the PEB floppy disk controller, I eliminated the flex cable interface as being a problem, tested my 32KB RAM expander and that works, the TI RS232 interface card works, and the FDC did not. I was able to probe using Mini Memory from the FinalGROM cartridge the various CRU bits on the FDC, and check the DSR ROMs on the card. The page >4000-4FFF worked, but >5000-5FFF returned all zeros. I probed with an o-scope the chip select lines from the PAL chip on the card, and the lower bank chip select worked, but not the upper one. You could see if wiggle just a little, but it was more of a sag. I suspected that the ROM itself was bad, so I pulled that from the board and probed the chip select line again. This time the line was able to be pulled all the way to 0. I happened to have a blank 2532 EPROM on hand, so I burned that EPROM with the DSR code and installed it in the FDC, and now I'm in business! I was able to initialize a disk successfully, and then save and load a BASIC program.

I haven't tried a downgrade from Jochen's firmware in circuit to the older firmware to see if the update works better for me with the newer firmware yet. That would probably be a good step to try.

I noticed on my board that the GROM data bus was not very square looking, but worked. You do need to have one of the three GROMs installed otherwise the system won't boot though... the other two are for TI BASIC and are not necessary to boot up.

Sorry for the delay... I got the firmware loaded using the programmer and... it works! In fact, it works much better than the v1.3 firmware on my unit. Several games wouldn't work at all if anything was plugged into the expansion connector (speech or PEB) and now they are working properly. I also tried the GROM test images from the github repo and that test passes too. This was on not one, but two non-QI units. One was an early black and silver, and the other a later one (no solid state cartridge badge with drop in overlay tray).

I think I'm going to try and reflow the CPLD and barring that working order a new one to put on the board.

Do you have a .bin file I can program out of circuit via the programmer?

Not exactly. After recovery with the v1.3 image, I attempted to load the cpld and avr update files in order. The updated cpld was accepted, the avr image however did the same fast blinkt thing as it did during the first attempt where it bricked, but this time I was able to recover to 1.3 with the same on target update process. I haven’t tried to load the updated firmware through the programmer yet. To be honest I’m wondering if something else is wrong with my final grom board. Several cartridges do not work correctly when there is anything plugged into the expansion port on the console, speech or peb. Without anything plugged in it seems to function correctly. At first I thought this was a problem with my console, but I’ve since borrowed another from a work friend and it behaves similarly with that one (though not precisely the same). I loaded the test software from the GitHub repo on the SD card and the grom tests flake out when things are connected to the console and run fine without. Maybe something marginal with the cpld programming or the cpld itself? Both consoles are black and silver. mine its an early one, my friends is a later one (no solid state cart badge and the tray for the overlays)

OK, I ran a couple of attempts again to run the update after recovering my board.... the first attempt failed with the quick flashing light, and required reprogramming out of circuit. The second attempt did the same thing, but was recoverable loading the old firmware and cpld code through the update process.

Huzzah! I'm back in business... replaced the AVR and reprogrammed and I'm running the v1.3 firmware again. I'll have to try the QI firmware update and see how that goes.

Just to reiterate... this is not an issue with the firmware... this was a result of me fat fingering the tool and messing up the fuse settings on the atmega.