Hi have now managed to load MBASIC onto one of the backup disks I received with the machine. There were two issues. The first was my fault in not understanding that when loading a file, the file extension should be omited. e.g.
Code:
A> WRITCAS MBASIC.COM
and
Code:
A> READCAS MBASIC
A> REN MBASIC.COM=MBASIC
The second issue is that, despite having two system disk backups, which look similar in terms of files on the disk etc. The commands behave differently. For example on one FORMAT.COM complains that the bios is not MFB, the second formats the disk as 80 track double density (and verifies) however, this cannot read or written to. I am assuming that some kind of check for MFB is present and causes it to fail. The bios used to create the disks clearly used the SYSTEMFW.CFG file. If I try and create a bios using MFB.CFG, GENSYS complains that the system track is not large enough but SYSTEMFW.CFG works fine.
Anyway enough babble, I ran your program i.e.
Code:
10 FOR I=0 TO 255 STEP 8
20 OUT &HE5,I+7
30 P=INP(&HE5)
40 PRINT HEX$(I+7),HEX$(P)
50 NEXT I
The output was...
Code:
7 7F
F 7F
17 7F
1F 5F
27 7F
2F 7F
37 7F
3F 1F
47 7F
4F 7F
57 7F
5F 5F
67 5F
6F 5F
77 5F
7F 1F
87 7F
8F 7F
97 7F
9F 5F
A7 7F
AF 7F
B7 7F
BF 1F
C7 3F
CF 3F
D7 3F
DF 1F
E7 1F
EF 1F
F7 1F
FF 1F
I hope this helps. Once you have this complete will it mean I will be able to emulate an MFB system with the Simon 4.1 ROM ? If so, that would be awesome.