External Memory Mapper

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By Erikie

Champion (324)

Erikie's picture

29-07-2009, 08:47

I have a problem with my 512Kb external mapper.
I bought this a couple of years ago and it works fine in my nms-8250's
Can see it with testmap and all checks out OK.
But when I insert it in a VG8020 or NMS8220 together with sunrise CF or my SD v2.2 the computer hangs. It does not even start properly.
Using only the mapper let the computer start but then I have no way of telling if the mapper even works or not. Don't know who the mapper made but if needed I can post an image of the PCB of the mapper

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By Leo

Paragon (1236)

Leo's picture

29-07-2009, 10:13

I have also a 512kb mapper , from PAdial it works on every msx1&2 i used .
Have you tried to switch slot1&2 between CF and mapper ?
....
if you type in basic , while booting only with mapper and without :

print hex$(inp(&hFF)) , hex$(inp(&hFE)) , hex$ (inp(&hFD)) , hex$(inp(&hFC))

what does it show ? FF FF FF FF ? or something else ?

and if you type
out(&hFC),12
print inp(&hFC)

what does it print ?

If you type, with no cartridge, then with mapper, on slot1, then mapper on slot2 :

print hex$(inp(a8))

the 8220 should have better support for mapper since it is msx2.

By Erikie

Champion (324)

Erikie's picture

29-07-2009, 11:39

Let me try this when I get home.
Indeed I tried different positions on the mapper and interfaces but no luck Sad

By pitpan

Prophet (3131)

pitpan's picture

29-07-2009, 12:28

I had the same problem when using a Padial 4 MB external mapper with a Philips VG8020. You can check the solution that worked for me here. In short: you need to init the mapper ports manually 'cause the MSX1 BIOS does not do the trick for you ;)

Retrotechie suggested the following:

OUT (#FF),0
OUT (#FE),1
OUT (#FD),2
OUT (#FC),3

And now everything works as a charm (Philips VG8020, slot expander x4, external 4 MB mapper, CF-IDE, SCC+, FM-PAC, MegaRAM / MegaFlash SCC). Quite a heavy weight for a poor and old MSX1 ;D

By Erikie

Champion (324)

Erikie's picture

29-07-2009, 12:31

I know the thread but I was thinking that at least the NMS8220 should be able to handle the mapper ...
However when I insert both the mapper and CF interface I do not even get a basic prompt. So something else is not working properly

By sunrise

Paragon (1091)

sunrise's picture

29-07-2009, 14:53

I have a vg8010 and cf and padial mapper, works like a charm.
Differences in chipset perhaps, I donot get this

By Erikie

Champion (324)

Erikie's picture

29-07-2009, 15:04

I think the problem lies in my mapper, cannot think it is either the CF or vg8020 or nms8220.
Will try the tests Leo suggested and I will upload a sharp image of the mapper. Maybe someone can then tell me what is wrong

By Leo

Paragon (1236)

Leo's picture

29-07-2009, 15:25

there is a typo on last trial , it should be

print hex$(inp(&ha8))

Have you checked you have last revision of CF bios ? last rev is 2.40 from 2005 i think.
i think i remember something has been updated so it can work on MSX1 ... not really sureQuestion

By usuario_msx2

Paladin (745)

usuario_msx2's picture

29-07-2009, 16:24

I had the same problem when using a Padial 4 MB external mapper with a Philips VG8020. You can check the solution that worked for me here. In short: you need to init the mapper ports manually 'cause the MSX1 BIOS does not do the trick for you ;)

And now everything works as a charm (Philips VG8020, slot expander x4, external 4 MB mapper, CF-IDE, SCC+, FM-PAC, MegaRAM / MegaFlash SCC). Quite a heavy weight for a poor and old MSX1 ;D
Hello Edu,
my vg8020/19 (no azerty keyboard :P) works fine, my config:

+RGB
+slot 1 not expanded (4mb ram)
+slot 2 not expanded (Y.Seo mmc reader with scc)
+slot 3.1 internal megaflashrom scc (switch in parallel port)
+slot 3.0 and 3.3 free (2 slots miniexpansor) for scc+,fmpac,etc

see it :)

es.geocities.com/usuario_msx2/8020_2.JPG

es.geocities.com/usuario_msx2/8020_1.JPG

best regards

By Leo

Paragon (1236)

Leo's picture

29-07-2009, 17:45

you have 3 x SCC !!
internal megaflash
external SCC+
SD +SCC

The 4mb mapper can be in an expanded slot ? ( i think so )

By Erikie

Champion (324)

Erikie's picture

29-07-2009, 20:40

Hi Leo,

I have done the things you asked me.
I have a NMS8220/00 (A) and VG8020/00 (B)
Reading the ports FF, FE, FD, FC
(A) 80, 81, 82, 83 (B) FF, 00, 02, 02
Doing Out(&HFC),12 then print inp(&hfc)
(A) 140 (B) 12

Last test of print hex$(inp(&Ha8))
(A) without MM: F0 in slot 1: D0 in slot 2: machine did not work Sad Have to check slot 2 allthough FM pac did work in that slot
(B) without MM: F0 in slot 1: D0 in slot 2: E0

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