Eshs
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|0xF5 | |0xF5 | ||
|Out | |Out | ||
- | |Misc value. | + | |Misc value. |
+ | {| border="1" cellpadding="2" cellspacing="0" | ||
+ | |'''Bit''' | ||
+ | |'''Description''' | ||
+ | |- | ||
+ | |1 | ||
+ | |is audio (1 = audio signal comes from a vertical counter (VA3), 0 = audio signal is low). | ||
+ | |- | ||
+ | |2,3 | ||
+ | |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. | ||
+ | |- | ||
+ | |4-7 | ||
+ | |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 |
Revision as of 19:37, 19 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.
| ||||||||
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.