This page has first time setup instructions for REMEMOrizer.
I'm not really covering building the board, programming the FPGA, and soldering it all together, just how to install it.
The process really boils down to these things :-
Your MTX may have 2 or 3 ROMs.
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If you remove the ROMs containing OS and BASIC, set the ROMs jumper "high". REMEMOrizer will provide replacements. These don't corrupt the RAM Disc and are modified so that the cassette load/save routines access virtual cassette tapes.
If you don't remove ROMs containing OS and BASIC, set the ROMs jumper "low". Your RAM Disc can be corrupted at boot time, and you won't have the ability to use virtual cassette tapes.
Warning: Do not set the jumper "high" if your MTX still has the ROMs containing OS or BASIC. Both the motherboard and REMEMOrizer will attempt to drive the bus when these ROMs are is accessed, which could result in permanant damage to the MTX and/or REMEMOrizer.
According to the PALASM at the top of p249 of the
Phoenix MTX Operators Manual, MTX500s with 2 ROMs have a bug in their
memory decoder PAL.
Motherboard DRAM memory is inappropriately visible in RELCPMH=1 mode,
RAM Page 0, addresses 0x0000-0x3fff.
If you have a 2 ROM MTX500, replace the memory decoder PAL with the
2_32 GAL supplied with REMEMOrizer.
According to the PALASM at the bottom of p250 of the
Phoenix MTX Operators Manual, MTX500s with 3 ROMs have a bug in their
memory decoder PAL.
Motherboard DRAM memory is inappropriately visible in RELCPMH=0 mode,
RAM Page 1, addresses 0x8000-0xbfff.
If you have a 3 ROM MTX500, replace the memory decoder PAL with the
3_32 GAL supplied with REMEMOrizer.
MTX500s with memory upgrades will have had fixed PALs installed. As REMEMOrizer provides a memory upgrade, it also needs the fixes above. Replacing the memory decoder PAL is safe to do, whether or not you plan to use the MTX500 with REMEMOrizer.
Warning: Do not attach REMEMOrizer to a MTX500 unless you've replaced the memory decoder PAL. Both the motherboard and REMEMOrizer will attempt to drive the bus when the clashing memory ranges of RAM are accessed, which could result in permanant damage to the MTX and/or REMEMOrizer.
If your MTX only has 32KB of RAM, set the MTX500 jumper "high". This causes REMEMOrizer to provide a RAM upgrade, using 32KB of its SRAM.
If your MTX has 64KB of RAM, set the MTX500 jumper "low".
Warning: Do not set the jumper "high" if your MTX has 64KB of RAM. Both the motherboard and REMEMOrizer will attempt to drive the bus when the top 32KB of RAM is accessed, which could result in permanant damage to the MTX and/or REMEMOrizer.
Note: If, like me, you bodged or didn't finish a memory upgrade, you may have an MTX000, ie: a MTX with no memory at all! If the MTX500 jumper is "high" and the ROMs jumper is also "high", then the modified OS ROM will notice the lack of memory and tell REMEMOrizer to also provide the lower 32KB RAM.
If you have an MTX512 S2, then your motherboard will have 4256 DRAMs and a different memory decoder PAL. This PAL makes 64KB (or more) available in RELCPMH=0 mode and 208KB available in RELCPMH=1 mode. Memory above 64KB will clash with the memory upgrade provided by REMEMOrizer.
Therefore, if you have a an MTX512 S2 with 2 ROMs, replace the PAL with
the 2_64_s2 GAL supplied with REMEMOrizer.
If you have an MTX512 S2 with 3 ROMs, replace the PAL with
the 3_64_s2 GAL supplied with REMEMOrizer.
This GAL only makes 64KB memory available in RELCPMH=1 mode.
Warning: Do not attach REMEMOrizer to an MTX512 S2 if you have not replaced the PAL. Both the motherboard and REMEMOrizer will attempt to drive the bus when high memory is accessed, which could result in permanent damage to the MTX and/or REMEMOrizer.
The RS232 card provides two functions. It provides RS232 ports, and it acts as a bridge to an FDX box (even if you don't have one connected). As a consequence, if the MTX tries to read ROM 4 or ROM 5, or input from ports 20H or higher, or if it detects DMA from the FDX, it will drive the MTX data bus. This is clearly incompatible with an SDX, and its incompatible with REMEMOrizer too. An SDX and REMEMOrizer have their own ROMs and ports at these locations.
Therefore, if you have an RS232 card, remove its PAL and replace it with the
serial GAL supplied with REMEMOrizer.
This prevents the RS232 card from acting as a proxy for an FDX which doesn't
exist.
Warning: Do not attach REMEMOrizer to an MTX with an RS232 card if you have not replaced the PAL. Both the RS232 card and REMEMOrizer will attempt to drive the bus at the same time, which could result in permanent damage to the RS232 card and/or REMEMOrizer.
If you have a ROM card with sockets for 4 8KB EPROMs, it is almost certainly making them visible in ROM slot 2. REMEMOrizer also provides a superset of ROM 2 functionality, as administered by the REZROM2.COM tool. So they'll clash.
The REZSPEC.COM ZX Spectrum Emulator software delivered with REMEMOrizer relies on the enhanced ROM 2 support in REMEMOrizer.
Approaches to deal with the clash include :-
REZROM2.COM to load
images of the ROMs into REMEMOrizers ROM 2.
The only downside of this is that REMEMOrizer has to steal memory
normally used for RAM Disc to provide ROM 2 support.
romcard3 to replace the PAL12L6
on the ROM card.
The little "games ROM" cards that had a single chip and were attached to the left hand side of the MTX typically decoded ROM 7, and are not a problem. The "language ROMs" that were piggy-backed on top of the main ROM also decoded ROM 7, and are also not a problem.
Connect the REMEMOrizer board to the connector on the left hand side of the MTX.
Connect a VGA monitor to the 15 pin D-sub connector at the top right of the REMEMOrizer.