Eshs
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(→Memory Map) |
(→Z80 Port Map) |
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|0xF5 | |0xF5 | ||
|Out | |Out | ||
- | |Misc value | + | |Misc value. Bit 1 is audio (1 = audio signal comes from a vertical counter (VA3), 0 = audio signal is low). Bit 2 and 3 deal with whether to show the laserdisc image or not. If bit 3 is high, A7 of the RGB prom is also high, laserdisc video is suppressed, and bit 2 is ignored. If bit 2 is high (and bit 3 is low) A7 of the RGB prom is low, and laserdisc video is suppressed. Bits 4-7 appear to decide whether A8 of the RGB prom is high/low depending on current position. This may be a way to have different pixels of a tile use a different color palette. |
|- | |- | ||
|0xF8 | |0xF8 | ||
|Out | |Out | ||
|0 disables start button lamp. 1 enables. | |0 disables start button lamp. 1 enables. | ||
+ | |- | ||
+ | |0xF9 | ||
+ | |Out | ||
+ | |Drives EDGE_06 (on the edge connector), but we don't know what this is connected to. | ||
|- | |- | ||
|0xFA | |0xFA | ||
Line 69: | Line 73: | ||
|Out | |Out | ||
|0 disables joystick lamp. 1 enables. | |0 disables joystick lamp. 1 enables. | ||
+ | |- | ||
+ | |0xFC | ||
+ | |Out | ||
+ | |Not connected | ||
+ | |- | ||
+ | |0xFD | ||
+ | |Out | ||
+ | |Not connected | ||
|- | |- | ||
|0xFE | |0xFE |
Revision as of 20:25, 18 August 2020
Contents |
Esh's Aurunmilla
Memory Map
Address Range | Description |
0x0000-0x1FFF | ROM H8 |
0x2000-0x3FFF | ROM F8 |
0x4000-053FFF | ROM E8 |
0x6000-073FFF | ROM D8 |
0x8000-0x9FFF | ROM C8 |
0xE000-0xE7FF | CPU RAM (B8) |
0xF000-0xF7FF | Video RAM (F3) |
Z80 Port Map
Address Range | Direction | Description |
0xF0 | In | Control panel input. Only lower 6 data bits are used. |
0xF1 | In | Control panel input. Only lower 6 data bits are used. |
0xF2 | In | Control panel input. Only lower 6 data bits are used. |
0xF3 | In | Control panel input. Only lower 6 data bits are used. |
0xF4 | In/Out | LD-V1000 data. Writing queues a command to be sent on the next command strobe. Reading reads the most recent byte received during last the status strobe. |
0xF5 | Out | Misc value. Bit 1 is audio (1 = audio signal comes from a vertical counter (VA3), 0 = audio signal is low). Bit 2 and 3 deal with whether to show the laserdisc image or not. If bit 3 is high, A7 of the RGB prom is also high, laserdisc video is suppressed, and bit 2 is ignored. If bit 2 is high (and bit 3 is low) A7 of the RGB prom is low, and laserdisc video is suppressed. Bits 4-7 appear to decide whether A8 of the RGB prom is high/low depending on current position. This may be a way to have different pixels of a tile use a different color palette. |
0xF8 | Out | 0 disables start button lamp. 1 enables. |
0xF9 | Out | Drives EDGE_06 (on the edge connector), but we don't know what this is connected to. |
0xFA | Out | 0 disables action button lamp. 1 enables. |
0xFB | Out | 0 disables joystick lamp. 1 enables. |
0xFC | Out | Not connected |
0xFD | Out | Not connected |
0xFE | Out | 0 holds IRQ' line high (disabled) by forcing a latch to be clear. 1 stops forcing latch to be clear, which allows IRQs to set the latch. |
0xFF | Out | 0 holds NMI' line high (disabled) by forcing a latch to be clear. 1 stops forcing latch to be clear, which allows NMIs to set the latch. |
Interrupts
NMI: Caused by LD-V1000 status strobe going low (becoming active)
IRQ: Caused by D2 output (pin 10) on vertical PROM (C6) transitioning from 0 to 1.