(original) (raw)
Updates
03 Jun 2023
Added .DSK image of original (and long sought after) MSX CP/M 2.2 boot disk (<MSXCPM.DSK> 720K)
MSX Network
- �������������� ������� BASIC, �.1
- �������������� ������� BASIC, �.2
- �������� MSX NET-BIOS
- ��������� �������� MSX NET-BIOS
- �������� ������������������� NET-BIOS, ������� ���� � �������������
- CP/M stuff
- Network module schematics, page 2
- ����\����2 ��p��� 1.16
- YM3802 abstract, datasheet
MSX-Link
This project's main goal was to have my diskless MSX2 (Yamaha YIS-503/IIIR) hooked to a PC that would emulate (well, actually simulate) another MSX2 machine, and with quite a bit of reverse engineering, programming, hacking and soldering to be able to download games using YIS-503/IIIR's built-in networking capabilities.
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This simple circut allows any MSX equipped with Network Module to be connected to any RS-232 port. Full opto-coupling (both TX and RX), no additional power supply (necessary voltages taken from MSX and RS-232).Schematics (JPG, 68K)PCB design (PostScript, 51K)Components layout (PostScript, 83K)Communicate using speed 38400, 8 bits and 2 (!) stopbits. At least it works for me this way. |
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Packet formats
Typical packet has a header, a payload, sometimes a checksum and terminator (0x97 if there will be more packets, 83 if this is the last packet in a sequence).
| HEADER | PAYLOAD | CHECKSUM | TERMINATOR | |||||
|---|---|---|---|---|---|---|---|---|
| F0 00 | Destination address | Packet type | Source address | Command (2 bytes - see Encoding) | Optional parameters (encoded) | Optional data byte(s) (encoded) | 16-bit checksum (encoded) | 97 (intermediate packet) 83 (last packet) |
Header
Source and destination address can be 00 (Teacher), 01..0F (Student), and 7F (Broadcast).
Command - see Packet 0x01 description.
Payload
Maximum data bytes (without optional parameters) - 58 bytes.
Checksum
Checksum is a 16-bit sum of all bytes in payload. Packets with wrong checksum are silently discarded.
Encoding
Each 8-bit byte is sent as a pair of 7-bit octets, with the first octet carrying only bit 7 of original byte, and the second carries bits 6..0. This allows for sending packets across MIDI-like network (and through YM3802 chip in particular) in accordance with MIDI standards.
Example: byte 21 is sent as 00 21; byte FF is sent as 01 7F.
There are four types of packets used in MSX network.
Packet 0x01
This is the Base type of packet. Each Base packet should be acknowledged with ACK (0x06) packet, except for specific ones (see table).
| 00 | 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 0A | 0B | 0c | 0d | 0e | 0f | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 1a |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| F0 | 00 | ADR2 | 01 | ADR1 | 00 | CMND | ||||||||||||||||||||
| CP/M | ||||||||||||||||||||||||||
| 20 NET-CLOSE-FILE | LNGTH | H | F | A | FCB (37 bytes) | CHKSUM | 83 | |||||||||||||||||||
| 21 NET-SEARCH-FIRST | LNGTH | H | F | A | FCB (37 bytes) | CHKSUM | 83 | |||||||||||||||||||
| 22 NET-SEARCH-NEXT | LNGTH | H | F | A | FCB (37 bytes) | CHKSUM | 83 | |||||||||||||||||||
| 23 NET-DELETE-FILE | LNGTH | H | F | A | FCB (37 bytes) | CHKSUM | 83 | |||||||||||||||||||
| 24 NET-READ-FILE | LNGTH | H | F | A | FCB (37 bytes) | CHKSUM | 83 | |||||||||||||||||||
| 25 NET-WRITE-FILE | LNGTH | H | F | A | FCB (37 bytes) | CHKSUM | 83 | |||||||||||||||||||
| 26 NET-CREATE-FILE | LNGTH | H | F | A | FCB (37 bytes) | CHKSUM | 83 | |||||||||||||||||||
| 27 NET-RENAME-FILE | LNGTH | H | F | A | FCB (37 bytes) | CHKSUM | 83 | |||||||||||||||||||
| 2c Master Data (first packet) | ||||||||||||||||||||||||||
| 2d Master Data (subsequent packets) | ||||||||||||||||||||||||||
| 2e NET-SEARCH-END | LNGTH | H | F | A | FCB (37 bytes) | CHKSUM | 83 | |||||||||||||||||||
| 2f NET-OPEN-FILE | LNGTH | H | F | A | FCB (37 bytes) | CHKSUM | 83 | |||||||||||||||||||
| 30 re: NET-CLOSE-FILE | ||||||||||||||||||||||||||
| 31 re: NET-SEARCH-FIRST | ||||||||||||||||||||||||||
| 32 re: NET-SEARCH-NEXT | ||||||||||||||||||||||||||
| 33 re: NET-DELETE-FILE | ||||||||||||||||||||||||||
| 34 re: NET-READ-FILE | ||||||||||||||||||||||||||
| 35 re: NET-WRITE-FILE | ||||||||||||||||||||||||||
| 36 re: NET-CREATE-FILE | ||||||||||||||||||||||||||
| 37 re: NET-RENAME-FILE | ||||||||||||||||||||||||||
| 3c Slave Data (first packet) | ||||||||||||||||||||||||||
| 3d Slave Data (subsequent packets) | ||||||||||||||||||||||||||
| 3e re: NET-SEARCH-END | ||||||||||||||||||||||||||
| 3f re: NET-OPEN-FILE | ||||||||||||||||||||||||||
| General | ||||||||||||||||||||||||||
| 40 SEND | LNGTH | byte 1 | byte 2 | bytes NN | CHKSUM | 97/83 | ||||||||||||||||||||
| 41 SEND | LNGTH | byte 1 | byte 2 | bytes NN | CHKSUM | 97/83 | ||||||||||||||||||||
| 42 SHEX (data packets) | ||||||||||||||||||||||||||
| 43 SHEXS (data packets) | ||||||||||||||||||||||||||
| 44 SEND-VRAM-DATA | ||||||||||||||||||||||||||
| 45 SHEXS (file data packets) | LNGTH | byte 1 | byte 2 | bytes NN | CHKSUM | 97/83 | ||||||||||||||||||||
| 46 MESS, TALK | LNGTH | byte 1 | byte 2 | bytes NN | CHKSUM | 97/83 | ||||||||||||||||||||
| 47 | ||||||||||||||||||||||||||
| 48 SNDCMD | LNGTH | byte 1 | byte 2 | bytes NN | CHKSUM | 97/83 | ||||||||||||||||||||
| 49 SNDM (first packet) | LNGTH | byte 1 | byte 2 | bytes NN | CHKSUM | 97/83 | ||||||||||||||||||||
| 4a SNDM (subsequent packets) | LNGTH | byte 1 | byte 2 | bytes NN | CHKSUM | 97/83 | ||||||||||||||||||||
| 4b re:RECV | LNGTH | byte 1 | byte 2 | bytes NN | CHKSUM | 97/83 | ||||||||||||||||||||
| 4c re:RHEX | LNGTH | byte 1 | byte 2 | bytes NN | CHKSUM | 97/83 | ||||||||||||||||||||
| 4d re:RHEXS data | ||||||||||||||||||||||||||
| 4e re:RHEXS (file) | LNGTH | byte 1 | byte 2 | bytes NN | CHKSUM | 97/83 | ||||||||||||||||||||
| 4f re:63 | ||||||||||||||||||||||||||
| 50 | ||||||||||||||||||||||||||
| 51 re:RCVM | LNGTH | byte 1 | byte 2 | bytes NN | CHKSUM | 97/83 | ||||||||||||||||||||
| 52 SHEX/SHEXS | START | END | 83 | |||||||||||||||||||||||
| 53 SEND-VRAM-REG | START | END | V_REGDAT (40 bytes) | 83 | ||||||||||||||||||||||
| 54 re:RHEXS header | START | END | V_REGDAT (40 bytes) | 83 | ||||||||||||||||||||||
| 55 SHEXS (file) | START | END | 83 | |||||||||||||||||||||||
| 56 re:RECEIVE-VRAM-REG | START | END | V_REGDAT (40 bytes) | 83 | ||||||||||||||||||||||
| 57 RHEX | START | END | 83 | Respond with 4c | ||||||||||||||||||||||
| 58 RHEXS (mem) | START | END | 83 | Respond with 54, then send 4d(s) | ||||||||||||||||||||||
| 59 RECEIVE-VRAM-REG | START | END | 83 | Respond with 56 | ||||||||||||||||||||||
| 5a RECEIVE-VRAM-DATA | START | END | 83 | Respond with 4e | ||||||||||||||||||||||
| 5b RHEXS (file) | START | END | 83 | Respond with 4e | ||||||||||||||||||||||
| 5c POKE | ADDR | byte 1 | 83 | |||||||||||||||||||||||
| 5d POKE (NetRAM) | ADDR | byte 1 | 83 | |||||||||||||||||||||||
| 5e RUN | ADDR | 83 | ||||||||||||||||||||||||
| 5f PEEK | ADDR | 83 | Respond with 61 | |||||||||||||||||||||||
| 60 PEEK (NetRAM) | ADDR | 83 | Respond with 61 | |||||||||||||||||||||||
| 61 re:PEEK | byte 1 | 83 | ||||||||||||||||||||||||
| 62 RECV | 01 7F 01 7F | 01 7F 01 7F | 83 | Respond with 4b | ||||||||||||||||||||||
| 63 | 83 | Respond with 4f | ||||||||||||||||||||||||
| 64 RCVM | 83 | Respond with 51 | ||||||||||||||||||||||||
| 65 STOP | 83 |
Packet 0x15 (PING)
Ping packet type. Every workstation upon receiving of this packet should respond with 0x05 (PONG) packet.
| 00 | 01 | 02 | 03 | 04 | 05 | 06 |
|---|---|---|---|---|---|---|
| F0 | 00 | ADR2 | 15 | ADR1 | O_STATUS | 83 |
Master workstation sends PING to all Slave workstations in turn (01..0F) when idle, to keep list of active Slaves up to date.
Packet 0x06 (ACK)
This packet is used to acknowledge the reception of most Base packets.
| 00 | 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 0a | 0b |
|---|---|---|---|---|---|---|---|---|---|---|---|
| F0 | 00 | ADR2 | 06 | ADR1 | U_STATUS | 83 |
Packet 0x05 (PONG)
Response to PING (0x15) packet.
| 00 | 01 | 02 | 03 | 04 | 05 |
|---|---|---|---|---|---|
| F0 | 00 | ADR2 | 05 | ADR1 | 83 |
Sending files from PC
MS-DOS executable: <msx-link.exe> (500K)
Source: https://github.com/mr-GreyWolf/MSX-Network
© 2005-2023 tnt23