*** M E M O R U M ***

In terms of hardware support, it would be possible to produce a custom version for the CFX-II. The speed would be in between that of M576ZVM and CPMVVM. The CFX-II has a silicon disk rather than extra memory for a RAM disk. With the silicon disk it is not possible to directly access individual bytes...

Martin, I am not surprised that you found M576ZVM to be significantly faster (well less slow). The cycle counts given in the earlier post are best case values obtained on MEMU and do not include cycles spent waiting for I/O. Also, they are taken at the start of the program, when M576ZVM is loading t...

Just tested. I can download either copy without any issues.

Uploaded again. Try this copy.

Martin, Those were both "issues" I inherited from the upstream version. Not checking which window is selected before outputting the prompt. Converting the character to upper case (and 0DFh) without first checking that the character is a letter. And you are quite right, the "invisible" character is 1...

Some further revisions to both versions of the ZVM emulator for Memotech. The issue with M576ZVM.COM was interesting. From the Memotech FDX Technical Manual (on Dave's site): 0045_Note.png So as I was filling each bank of RAM (48KB) with the contents of the story file, the byte at 0x0045 in each ban...

Looking further into the screen handling code I have uncovered an obscure but real bug in the MTX ROM. It is in ROM 1: 39B0 F1 crscr2: POP AF 39B1 AF XOR A 39B2 BA CP D 39B3 28 FB JR Z, crscr2 39B5 BB CP E 39B6 28 F8 JR Z, crscr2 It is triggered if you do a CRVS statement with either the width (para...

Martin, At the moment, I cannot even begin to imagine why one version of the software should print commas correctly and not the other :? Need to be careful about which version you are calling the "virtual memory" version: cpmzvm.com uses only 64KB of real memory and therefore uses virtual memory, sw...

Martin, The 191230 zip file contains a bug fixed version of CPMZVM as well as the large RAM version, M576ZVM. I suggest you try that. I have never got very far, but certainly Zork will respond reasonably to a few commands: Zork_Progress.png This is running on MEMU, in order to be able to debug the c...

I have been looking at the ROM code for screen handling and have discovered a few character sequences that can be used to control the screen, that are not documented in either version of the MTX manual: <Ctrl+X> - Sets white text on a black background. <Esc>, "L" - Reads the character under the curs...