Press n or j to go to the next uncovered block, b, p or k for the previous block.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 | 2784x 56x 3489x 967x 7x 7828x 7x 7x 7x 7x 7x 7x 7x 866x 862x 862x 862x 862x 862x 15x 15x 4x 847x 847x 10x 862x 862x 14878x 825x 104221x 338661x 5732x 5732x 99460x 15192x 15192x 29407x 29407x 217x 217x 15192x 207x 206x 207x 207x 12x 12x 9x 9x 62x 60x 9x 2x | import { hexword } from "./hex.js";
import { NoiseAwareIntelFdc } from "./intel-fdc.js";
import { NoiseAwareWdFdc } from "./wd-fdc.js";
/**
* Which chip answers where in SHEILA (&FE00-&FEFF) on each BBC model, and what its registers are called, read
* and written. The ranges follow the hardware's address decoding.
*
* @typedef {object} SheilaRegister
* @property {string | undefined} read - undefined where the chip doesn't answer a read
* @property {string | undefined} write - undefined where the chip doesn't take a write
*
* @typedef {object} SheilaBlock
* @property {string} device - short, to prefix a register's name: "SysVIA"
* @property {string} title - "System VIA"
* @property {number} start
* @property {number} end - exclusive
* @property {SheilaRegister[]} registers - by offset from `start`, repeating up to `end`
*
* @typedef {object} SheilaFittings
* @property {import("./models.js").Model} model
* @property {boolean} hasTube
* @property {boolean} hasEconet
* @property {boolean} hasVideoNula
*
* @typedef {{block: SheilaBlock, name: string}} SheilaName
*/
const both = (name) => ({ read: name, write: name });
const readOnly = (name) => ({ read: name, write: undefined });
const writeOnly = (name) => ({ read: undefined, write: name });
const readWrite = (read, write) => ({ read, write });
const Unanswered = { read: undefined, write: undefined };
const block = (device, title, start, end, registers) => ({ device, title, start, end, registers });
const ViaRegisters = [
readWrite("IRB", "ORB"),
readWrite("IRA", "ORA"),
both("DDRB"),
both("DDRA"),
readWrite("T1CL", "T1LL"),
both("T1CH"),
both("T1LL"),
both("T1LH"),
readWrite("T2CL", "T2LL"),
both("T2CH"),
both("SR"),
both("ACR"),
both("PCR"),
both("IFR"),
both("IER"),
readWrite("IRA_NH", "ORA_NH"),
];
const Intel8271Registers = [
readWrite("STATUS", "COMMAND"),
readWrite("RESULT", "PARAMETER"),
readWrite("COUNT_HI", "RESET"),
readOnly("COUNT_LO"),
both("DATA"),
both("DATA"),
both("DATA"),
both("DATA"),
];
const Wd1770Registers = [
writeOnly("CONTROL"),
writeOnly("CONTROL"),
writeOnly("CONTROL"),
writeOnly("CONTROL"),
readWrite("STATUS", "COMMAND"),
both("TRACK"),
both("SECTOR"),
both("DATA"),
];
const DiscControllers = new Map([
[NoiseAwareIntelFdc, { title: "8271 disc controller", registers: Intel8271Registers }],
[NoiseAwareWdFdc, { title: "1770 disc controller", registers: Wd1770Registers }],
]);
const AdcRegisters = [readWrite("STATUS", "START"), readOnly("HIGH"), readOnly("LOW"), Unanswered];
// Register 1 is CR3 and register 3 CR4 when CR1's address control bit is set.
const AdlcRegisters = [
readWrite("SR1", "CR1"),
readWrite("SR2", "CR2"),
readWrite("RXDATA", "TXDATA"),
readWrite("RXDATA", "TXLAST"),
];
const TubeRegisters = [
readWrite("R1STAT", "CONTROL"),
both("R1"),
readOnly("R2STAT"),
both("R2"),
readOnly("R3STAT"),
both("R3"),
readOnly("R4STAT"),
both("R4"),
];
/**
* The blocks of SHEILA on the machine `fittings` describe, none on an Atom, which has no SHEILA. A block answers
* only some of its addresses in each direction, and at most one block answers each address in each direction.
* @param {SheilaFittings} fittings
* @returns {SheilaBlock[]}
*/
export function sheilaBlocks({ model, hasTube, hasEconet, hasVideoNula }) {
if (model.isAtom) return [];
const disc = DiscControllers.get(model.Fdc);
const videoUla = [writeOnly("CONTROL"), writeOnly("PALETTE")];
if (hasVideoNula) videoUla.push(writeOnly("NULA_CONTROL"), writeOnly("NULA_PALETTE"));
const blocks = [
block("CRTC", "6845 CRTC", 0xfe00, 0xfe08, [both("ADDR"), both("DATA")]),
block("ACIA", "6850 ACIA", 0xfe08, 0xfe10, [readWrite("STATUS", "CONTROL"), both("DATA")]),
block("SerialULA", "Serial ULA", 0xfe10, 0xfe18, [writeOnly("CONTROL")]),
block("SysVIA", "System VIA", 0xfe40, 0xfe60, ViaRegisters),
block("UserVIA", "User VIA", 0xfe60, 0xfe80, ViaRegisters),
];
if (model.isMaster) {
blocks.push(
block("ADC", "7002 ADC", 0xfe18, 0xfe1c, AdcRegisters),
block("VideoULA", "Video ULA", 0xfe20, 0xfe24, videoUla),
block("FDC", disc.title, 0xfe24, 0xfe2c, disc.registers),
block("Paging", "ROM select", 0xfe30, 0xfe34, [both("ROMSEL")]),
block("Paging", "Access control", 0xfe34, 0xfe38, [both("ACCCON")]),
);
if (hasEconet)
blocks.push(
block("Econet", "Econet station and interrupt off", 0xfe38, 0xfe3c, [both("INTOFF")]),
block("Econet", "Econet interrupt on", 0xfe3c, 0xfe40, [readOnly("INTON")]),
);
} else {
blocks.push(
block("VideoULA", "Video ULA", 0xfe20, 0xfe30, videoUla),
block("Paging", "ROM select", 0xfe30, 0xfe40, [writeOnly("ROMSEL")]),
block("FDC", disc.title, 0xfe80, 0xfea0, disc.registers),
block("ADC", "7002 ADC", 0xfec0, 0xfee0, AdcRegisters),
);
if (hasEconet)
blocks.push(
block("Econet", "Econet station and interrupt off", 0xfe18, 0xfe20, [both("INTOFF")]),
block("Econet", "Econet interrupt on", 0xfe20, 0xfe30, [readOnly("INTON")]),
);
}
if (hasEconet) blocks.push(block("ADLC", "6854 ADLC", 0xfea0, 0xfec0, AdlcRegisters));
if (hasTube) blocks.push(block("Tube", "Tube ULA", 0xfee0, 0xff00, TubeRegisters));
return blocks.sort((a, b) => a.start - b.start);
}
/**
* The blocks of SHEILA on the machine `cpu` emulates.
* @param {import("./6502.js").Cpu6502} cpu
*/
export function machineSheilaBlocks(cpu) {
return sheilaBlocks({
model: cpu.model,
hasTube: cpu.hasTube,
hasEconet: !!cpu.econet,
hasVideoNula: cpu.video.ula.hasVideoNula,
});
}
/**
* The register `address` reads or writes, by `access`.
* @param {SheilaBlock[]} blocks
* @param {number} address
* @param {"read" | "write"} access
* @returns {SheilaName | undefined}
*/
export function sheilaRegister(blocks, address, access) {
for (const block of blocks) {
if (address < block.start || address >= block.end) continue;
const name = block.registers[(address - block.start) % block.registers.length][access];
if (name !== undefined) return { block, name };
}
return undefined;
}
/**
* What an instruction accessing `address` the ways `accesses` lists touches, named once per chip: a read-modify-write
* of a VIA's ORB is "SysVIA.IRB/ORB".
* @param {SheilaBlock[]} blocks
* @param {number} address
* @param {("read" | "write")[]} accesses
* @returns {{name: string, title: string} | undefined}
*/
export function sheilaName(blocks, address, accesses) {
const byBlock = new Map();
for (const access of accesses) {
const found = sheilaRegister(blocks, address, access);
if (!found) continue;
if (!byBlock.has(found.block)) byBlock.set(found.block, new Set());
byBlock.get(found.block).add(found.name);
}
if (!byBlock.size) return undefined;
const each = [...byBlock].map(([block, names]) => ({ block, names: [...names].join("/") }));
return {
name: each.map(({ block, names }) => `${block.device}.${names}`).join("/"),
title: `${each.map(({ block, names }) => `${block.title} ${names}`).join(" / ")}: $${hexword(address)}`,
};
}
/**
* The address of the register `text` names as the disassembly shows it, such as "SysVIA.ORB", in any case.
* @param {SheilaBlock[]} blocks
* @param {string} text
* @returns {number | undefined}
*/
export function sheilaAddress(blocks, text) {
const parts = text.toUpperCase().split(".");
if (parts.length !== 2) return undefined;
const [device, name] = parts;
for (const block of blocks) {
if (block.device.toUpperCase() !== device) continue;
const offset = block.registers.findIndex(({ read, write }) => read === name || write === name);
if (offset >= 0) return block.start + offset;
}
return undefined;
}
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