An ASCII listing is at the end.  The following description was
written by Steve Sheppard.

Located at FD00

grant@stockly.com

"Mon88PMC" is a modified 1702A Turnkey Monitor ("TurMon") EPROM, to 
be used in any Altair 8800 series computer.

As with the TurMon, there are three commands:
M - Memory examine and change
D - Binary memory dump
J - Jump to user program and run - ie, run a user program at
memory location 000000, or execute a bootstrap program 
located in EPROM.

The chip helps when troubleshooting your Altair- you can load and 
execute programs from a key board, deposit and examine memory, etc. 
It allows you to do everything the TurMon Turnkey Monitor PROM can 
do, but unlike the TurMon chip that can only be installed in the 
Altair 88-TKY Turnkey board, the Mon88PMC can also be installed in 
the MITS 88-PMC 2K PROM board. Therefore, it will run in the Altair 
8800/8800A. The standard TurMon chip only works with the 8800b 
because it only works with the 88-TKY Turnkey board*, and the TKY 
board only works in the 8800b.

In addition to your regular RAM installed beginning at address 
000000, you will need to have stack memory for the Mon88PMC installed 
at 56K (160000/E000)** to 60K (170000/F000). There can be a gap 
between the top of regular memory and the stack memory. Mon88PMC 
executes from the same memory location as the TurMon (176400/FD00). 
You'll have to be sure your PMC board is properly addressed (it 
probably is already). You'll need the TurMon instruction manual, too.

The TurMon chip's code was modified to move its stack to a new 
location at 60K (170000/F000). There were only two changes to the 
TurMon's code:

Address 000012/000A TurMon data= 374/FC Mon88PMC data= 360/F0
Address 000017/000F TurMon data= 056/2E Mon88PMC data= 043/23

The Mon88PMC code was written by Andrew Kessel or, stated more 
accurately, Andrew modified the existing TurMon code, which was 
written by MITS. 

...

*The TurMon requires and uses 1K of memory addressed just below the 
TurnKey board's EPROMs at 174000/F800 to 175777/DFFF. TurMon won't 
work on the PMC 2K PROM board because there are EPROMS addressed at 
those memory locations. The Mon88PMC simply uses memory at a 
different address where there will be no conflicts.

**All addresses are given as octal/hex. 
==============================================================


3E
03
D3
10
3E
11
D3
10
31
00
F0
CD
9D
FD
3E
23
CD
F2
FD
CD
E8
FD
FE
4D
CA
29
FD
FE
44
CC
4F
FD
FE
4A
C2
08
FD
CD
A7
FD
E9
CD
A7
FD
3E
23
CD
9D
FD
54
5D
CD
C9
FD
1A
67
CD
CF
FD
CD
A8
FD
EB
DA
2D
FD
77
BE
CA
2D
FD
3E
3F
CD
F2
FD
C3
08
FD
CD
A7
FD
EB
D4
E3
FD
CD
A7
FD
3E
0D
06
3C
CD
F2
FD
05
C2
5D
FD
B8
78
C2
5B
FD
7D
93
6F
7C
9A
67
23
05
7C
B7
C2
77
FD
45
3E
3C
CD
F2
FD
78
CD
F2
FD
0E
00
7B
CD
F2
FD
7A
CD
F2
FD
1A
CD
F2
FD
13
2B
05
C2
8A
FD
79
CD
F2
FD
7C
B5
C2
70
FD
3E
0D
CD
F2
FD
3E
0A
C3
F2
FD
06
06
03
21
00
00
CD
E8
FD
4F
FE
20
37
C8
E6
B8
EE
30
C2
47
FD
79
E6
07
29
29
29
85
6F
05
C2
AD
FD
C9
06
06
AF
C3
D6
FD
06
03
E6
29
17
29
17
29
17
E6
07
F6
30
CD
F2
FD
05
C2
D2
FD
3E
20
C3
F2
FD
DB
10
0F
D2
E8
FD
DB
11
E6
7F
F5
81
4F
DB
10
0F
0F
D2
F5
FD
F1
D3
11
C9