Article View: comp.sys.atari.st
Article #37749Mega ST with old roms - now it works
From: Walter Holzer
Date: Wed, 05 Apr 1989 11:47
Date: Wed, 05 Apr 1989 11:47
60 lines
3044 bytes
3044 bytes
Ok, here it is, the completly workaround to work with old rom's in mega st.
There was a mistake in the translation table, but now it will works.
You'll have to do the following things:
- Jumper W2 from 2-3 to 1-2
- Jumper W3 from 2-3 to 1-2
- Close Jumper W4
- Plug out chip U12 (or disable pin 12).
Have fun it's working in my mega st
-- Matthias
====================================================================
Uxx = U<socket> ! will be in ! adress
in 260/520/520+ ! MEGA ST2/4 !
Board <= Rev.H ! !
----------------+------------+--------------------------
TOSyyyy.U2 ! *.U3 ! $FE0000-$FEFFFF, HiBytes
TOSyyyy.U3 ! *.U6 ! $FD0000-$FDFFFF, HiBytes
TOSyyyy.U4 ! *.U9 ! $FC0000-$FCFFFF, HiBytes
TOSyyyy.U5 ! *.U4 ! $FE0000-$FEFFFF, LoBytes
TOSyyyy.U6 ! *.U7 ! $FD0000-$FDFFFF, LoBytes
TOSyyyy.U7 ! *.U10 ! $FC0000-$FCFFFF, LoBytes
====================================================================
Schematic diagram:
U4 (label in Mega ST) U3 (label in Mega ST)
+--------------------+ +--------------------+
! was TOS.U5 ! ! was TOS.U2 !
! in older ST's ! ! in older ST's !
+--------------------+ +--------------------+
U7 (label in Mega ST) U6 (label in Mega ST)
+--------------------+ +--------------------+
! was TOS.U6 ! ! was TOS.U3 !
! in older ST's ! ! in older ST's !
+--------------------+ +--------------------+
U10 (label in Mega ST) U9 (label in Mega ST)
+--------------------+ +--------------------+
! was TOS.U7 ! ! was TOS.U4 !
! in older ST's ! ! in older ST's !
+--------------------+ +--------------------+
W4
o
! +--------+ plug out complete chip or
! ! U12 ! <---- disable pin 12
o +--------+
1 2 3 1 2 3
o--o o o--o o
W2 W3
====================================================================
--
Walter Holzer & Matthias Dominick Internet: holzer@ztivax.siemens.com
UUCP: holzer@ztivax.UUCP or : uunet!mcvax!unido!ztivax!holzer
XNS : Dominick:ZTISOF:SIEMENS FidoNet : Matthias Dominick on 2:507/414.28
Herman Munster said: "I've got it! I've got it! I've got it! ..."
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arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!shadooby!accuvax.nwu.edu!tank!shamash!nic.MR.NET!indri!csd4.milw.wisc.edu!lll-winken!uunet!mcvax!unido!ztivax!holzerShow Full Headers
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!shadooby!accuvax.nwu.edu!tank!shamash!nic.MR.NET!indri!csd4.milw.wisc.edu!lll-winken!uunet!mcvax!unido!ztivax!holzer From: holzer@ztivax.UUCP (Walter Holzer) Newsgroups: comp.sys.atari.st Subject: Mega ST with old roms - now it works Message-ID: <657@ztivax.UUCP> Date: 5 Apr 89 11:47:51 GMT Reply-To: holzer@ztivax.UUCP (Walter Holzer) Organization: Siemens AG in Munich, W-Germany Lines: 60