Idea: substitute ROM “MEI 1987 / DA1024D0365R” with a EEPROM 27C series
To Read the ROM chip, my EPROM Programmer (TL866CS) currently don’t support this model of ROM, so I plugged in with pin 1 of ROM into pin 3 of socket, rise pins 22 and 28, wired pin 28 to vcc (pin 32?? pin 2?? of socket)
How to read ROM “MEI 1987 / DA1024D0365R”
- Rise ROM pins 22 and 28
- Plugged this ROM into a Programmer’s socket with pin 1 of ROM into pin 3 of socket
- wire pin 28 of ROM to VCC (socket empty pin 32)
- wire pin 22 of ROM to A16 (socket empty pin 2)
- choose chip type as EEPROM 27C010
- after read, will have a file with 128KB
sha1: 9a62d7a5ccda974261f7c0600476d85e10deb99bsha256: 6A878A86B7B5E7E4EAAE82E1DF175D1EAFB20F813FC7157AB6AFF9506736B420
ROM “DA1024D0365R” Contents
| offset begin | offset end | size | function |
|---|---|---|---|
| 00000h | 07FFFh | 32KB | Main-ROM |
| 08000h | 0BFFFh | 16KB | Sub-ROM |
| 0C000h | 0FFFFh | 16KB | Disk-ROM |
| 10000h | 17FFFh | 32KB | Kanji driver |
| 18000h | 1FFFFh | 32KB | A1 Cockpit |
MSX Panasonic FS-A1F physical view ROM contents
| Addresses | slot 0 | slot 3-1 | slot 3-2 | slot 3-3 |
|---|---|---|---|---|
| C000-FFFF | ||||
| 8000-BFFF | Kanji driver | A1 Cockpit | ||
| 4000-7FFF | Main-ROM | Kanji driver | Disk ROM | A1 Cockpit |
| 0000-3FFF | Main-ROM | Sub-ROM |
MSX Panasonic FS-A1F logic view of ROM contents
REF: https://www.msx.org/wiki/Panasonic_FS-A1F
References
- MSX2 Panasonic FS-A1F wiki tutorials
- FS-A1FX Rom with FM Music and no Cockpit
- Output Enable Vs. Chip Select
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Many memory devices designed to connect to a bus (such as RAM and ROM chips) have both CS (chip select) and OE (output enable) pins, which superficially appear to do the same thing. If CS is not asserted, the outputs are high impedance.
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The difference lies in the time needed to output the signal. When chip select is deasserted, the chip does not operate internally, and there will be a significant delay between providing an address and receiving the data. (An advantage of course, is that the chip consumes minimal power in this case.)
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