Floppy Drives with TrumpMini3 Woes

[XorA]

I have been lead to believe that the trump 512K card didn't do the ROM switcheroo that the bigger one did, so the ROM doesn't disappear from 0xC0000 and therefore RES_128 would have still detected disk rom.

On the 768 if there is no RAM at 0xC0000 for a dummy copy of the ROM, there is no way for JS to ever find the ROM. So if your using the 768K gals and switching logic but only 512K of RAM you are breaking the system!

[t0nyt]

From what I’ve read the 256k (or 512k) Trump just needed the necessary RAM added to the board to become a 768k with no PAL change required

I’m more confused than ever

EDIT: also with just 512k it works perfectly other than the issue of a res_128 or reset xxx

[XorA]

From what I’ve read the 256k (or 512k) Trump just needed the necessary RAM added to the board to become a 768k with no PAL change required

I’m more confused than ever

EDIT: also with just 512k it works perfectly other than the issue of a res_128 or reset xxx

There is really no way that can be true based on the disassembly of RES_128 command Derek did!

[XorA]

Also Im pretty sure I disassembled a trump 512 rom a few years ago and it was different in its initialization!

[t0nyt]

From what I’ve read the 256k (or 512k) Trump just needed the necessary RAM added to the board to become a 768k with no PAL change required

I’m more confused than ever

EDIT: also with just 512k it works perfectly other than the issue of a res_128 or reset xxx

There is really no way that can be true based on the disassembly of RES_128 command Derek did!

Thanks XorA, which part can't be true please?

It definitely works perfectly with 512kb (other than reset_128 and reset xxx)

So I assume you mean the upgrade part please?

Many thanks
Tony

[t0nyt]

Can you indicate me the exact configuration do you have?
Including versions of gals and Roms, PCB (perhaps a picture) and jumpers?

There were some develop of each of this elements, and first I need to clarify what are you using.

Have read the GAL and it looks identical to the one on your GitHub

Many Thanks
Tony

[t0nyt]

From what I’ve read the 256k (or 512k) Trump just needed the necessary RAM added to the board to become a 768k with no PAL change required

I’m more confused than ever

EDIT: also with just 512k it works perfectly other than the issue of a res_128 or reset xxx

There is really no way that can be true based on the disassembly of RES_128 command Derek did!

Thanks XorA, which part can't be true please?

It definitely works perfectly with 512kb (other than reset_128 and reset xxx)

So I assume you mean the upgrade part please?

Many thanks
Tony

There is a jumper on the MT3 that selects if the extra 256KB is installed or not, so maybe that's where the confusion lays?

If you try and run the MT3 with just 256kb of RAM expansion it goes mad and scrolls the contents of a ROM on the screen

[t0nyt]

If you try and run the MT3 with just 256kb of RAM expansion it goes mad and scrolls the contents of a ROM on the screen

I wonder if that's where the problem is

[aalea]

First of all, this is a modification of my interface, I did was not aware that this version exist, and I'm not sure what it do or what kind of revision the maker use to do it, but assume that this is the last, based on the jumper of the top. (btw f|@¬½k the only things that the License of the PCB request is not change the notices, author, copyright, etc... and provide sources, and none is fulfill).

My version of the gal of the trump card, AFAIK like the one of tetroid or the original always do the mapping of the ROM after boot, I assume that the ROM is not reallocatable, and always need to work from the same memory position, based on the idea that there are several version of the interface (0Kb, 256Kb(ace), +256Kb(trey), 512 and 768kb).

In any case, the hardware of the "disk part" is always the same, and is located in the same areas of ram at different stages of boot.
The first 512Kb, are always located in a fixed way in the same position of memory.

What is different is the last 256Kb of RAM, that need to shared memory space with the "disk part" at initial stage of ram, this is the reason you can not use the Qsound with the JS version of the minitrump card, because the conflict of memory at boot.

On the original Trump Card, this is managed by the 2nd GAL, that disable this area of RAM at boot, this is internal wiring.

Because I design the RAM expansion first, and later the minitrump, and they are physically separated hardware, In the last version I reuse a unused line of the port expansion to comunicate the minitrump with the extra +256Kb, to disable it at boot stage.

So I supose that this jumper is to enable or disable this line, really nothing happend if you leave alwais as installed, because this line is not in use.
Also my +256Kb RAM has a jumper (popopo version has a switch) for the same propouse, but repeat, you can leave alwais on, and nothing happend.

What I mean is that there are no diferences, of any kind between using 768Kb, 512Kb, or 0Kb, apart that during a small time at boot part of the extra ram is disabled, like in the original trump.

[aalea]

If you try and run the MT3 with just 256kb of RAM expansion it goes mad and scrolls the contents of a ROM on the screen

This is strange and shall not happend, perhaps there are some changes in the interface I'm not aware.

You can't install only MT3 and +256Kb of RAM, and alwais install the +256Kb of RAM AFTER the MT3, never before (never at right), this is because the line that disable the RAM is only in the outside port of the MT3.

If you use the minerva version of the GAL, you can install whatever order you want, but remember that QL need a continuous RAM space, so if you install only +256KB QL will not detect and inform of only 128Kb.