Myarc 512K card modification

[RickyDean]

I have looked around at whtech.com, but not finding documentation on the conversion of a foundation 128/512 card to a myarc card. I have two that I converted, from the above mentioned Myarc 512k conversion and it seems they worked in the past. but I cannot get one to show a led, and neither comes up when i try to do a CALL RDTEST. All the chips have been tested/replaced as necessary and I replaced the led on the one not working last night, and installed two new eproms, still not working. So I am leaning toward a bad transistor, or something. But there was rewiring to do on the back of the card to be able to use the 512k memory dram and I want to be sure this was wired correctly. Can anyone point me to a doc/schematic source? Thanks

[+Schmitzi]

 

I don´t know if this is interesting, but I found another info from Paolo´s repository:

 

Myarc 512K Bugs.pdf

 

 

 

And just the MOD, just to have it here on AA:

 

Myarc512K-MODIF.pdf

 

 

 

And the original manual:

 

Myarc Memory Expansion Card.pdf

 

 

[+Schmitzi]

 

And this.

Due to the files date, I think I extracted this (and the "Bugs" ?)  from Paolo´s floppy DSK 2 years ago. But not sure.

 

Myarc RAMdisk.pdf

 

 

[+9640News]

32 minutes ago, Schmitzi said:

 

I don´t know if this is interesting, but I found another info from Paolo´s repository:

 

Myarc 512K Bugs.pdf 17.66 kB · 3 downloads

 

 

 

And just the MOD, just to have it here on AA:

 

Myarc512K-MODIF.pdf 58.75 kB · 3 downloads

 

 

 

And the original manual:

 

Myarc Memory Expansion Card.pdf 10.9 MB · 3 downloads

 

 

This looks like the instructions I used to modify my Myarc 512K card last year.

[+Schmitzi]

 

I found an interesting letter from Paolo Bagnaresi in his legacy files, that he wrote to a Mr. Miller

It´s about Myarc, floppy controllers, the PEB, and how to crash a card

 

Paolos-Letter-to-Beery-12.Feb.1990.pdf

[+Schmitzi]

 

Hi,

 

does the Myarc 512K (Geneve-modded) card interfere in any way with the 384K-mod (PFM+) on the Geneve ?

Or th 32K upgrade that I don´t know anything about ?

Or any other upgrade like 394K (non-PFM) (what I have)

 

Means, is the 384K upgrade (or any other) obsolete when using the Myarc 512K card,

means the 512K card OR the PFM/384K ONLY ?

 

Background: I have a PFM 128K modded Geneve (+384K SRAM + 192K Video RAM upgrade)

AND a standard Geneve, so thinking about what to do now.

 

thx.

 

 

[+Schmitzi]

So this is what I have collected for the Mods & Upgrades so far:

 

:

 

 

And just a shot to my Eproms section, but this is still wild

 

 

[RickyDean]

8 hours ago, Schmitzi said:

 

Hi,

 

does the Myarc 512K (Geneve-modded) card interfere in any way with the 384K-mod (PFM+) on the Geneve ?

Or th 32K upgrade that I don´t know anything about ?

Or any other upgrade like 394K (non-PFM) (what I have)

 

Means, is the 384K upgrade (or any other) obsolete when using the Myarc 512K card,

means the 512K card OR the PFM/384K ONLY ?

 

Background: I have a PFM 128K modded Geneve (+384K SRAM + 192K Video RAM upgrade)

AND a standard Geneve, so thinking about what to do now.

 

thx.

 

 

No it does not interfere, I used two of them on my PFM+ Geneve, after I got it back from Cecure, and Tim had installed the PFM+ on it. Could run the memory test and see alot of good usable memory.

[+Schmitzi]

47 minutes ago, RickyDean said:

No it does not interfere, I used two of them on my PFM+ Geneve, after I got it back from Cecure, and Tim had installed the PFM+ on it. Could run the memory test and see alot of good usable memory.

 

ah OK, so again, the PFM128/384 is "only" a FlashDisk, for faster booting and so on, right ?

 

But what happens if I have 384K (nonPFM = S-RAM) and add the Myarc 512K Card to the system,

does MDOS add/see/use this 896KB RAM as "one" RAM-area, or are they used/organized/programmed  somehow separately ?

 

 

 

 

[mizapf]

The PFM is a replacement for the boot EPROM. It appears in pages F0-FF, see https://www.ninerpedia.org/wiki/Geneve_physical_memory_map.

 

(PFM512 and Myarc memory expansion are also properly emulated in MAME, if you'd like to try it.)

Edited February 16 by mizapf