Changes between Version 11 and Version 12 of TeradriveHardwareNotes

Timestamp:

08/24/2024 05:19:03 AM (6 weeks ago)

Author:

Mike Pavone

Comment:

--

TeradriveHardwareNotes

@@ -5 +5 @@
 The Mega Drive side is most similar to a MD1 VA3 or VA4, but has some important differences. The Z80 has 16 KiB of RAM instead of the normal 8 KiB and the VDP has 128 kiB instead of the normal 64 kiB. It has a discrete YM3438 instead of a YM2612 as found in other pre-VA7 MD1 systems. It has the same "fix" for incorrect status port reads as found in MD systems with an integrated YM3438, but implemented as discrete logic. For the 68K it has a 10MHz rated 68HC000 which runs at either the standard speed or 10MHz depending on the mode.
 
-Joining the two is the IBM 79F2661 "bus switch". In addition to providing a bridge between the MD-side 68K bus and the ISA bus on the PC side, this chip also manages access to an extra 512 KiB ROM. This ROM contains a Kanji font, a ROM disk image for the boot menu and some firmware for the MD-side that implements a Teradrive specific variant of TMSS. This chip is also found in the PS/55 5510Z where it presumably is also used for Kanji ROM management.
+Joining the two is the IBM [wiki:79F2661] "bus switch". In addition to providing a bridge between the MD-side 68K bus and the ISA bus on the PC side, this chip also manages access to an extra 512 KiB ROM. This ROM contains a Kanji font, a ROM disk image for the boot menu and some firmware for the MD-side that implements a Teradrive specific variant of TMSS. This chip is also found in the PS/55 5510Z where it presumably is also used for Kanji ROM management.
 
 == 286 Memory Map