Difference between revisions of "Machine Type Register"
From SpecNext official Wiki
(Making this more in sync with web docs about ports, and removing non-existent links.) |
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{{NextRegister | {{NextRegister | ||
|Number=$03 | |Number=$03 | ||
| − | |Readable= | + | |Readable=Yes |
|Writable=Yes | |Writable=Yes | ||
|ShortDesc=Identifies timing and machine type. | |ShortDesc=Identifies timing and machine type. | ||
}} | }} | ||
| − | Only valid in [[IPL]] or config mode. | + | Only valid in [[IPL]] or config mode (0x0000-0x3FFF are mapped to the RAM instead of the internal ROM). |
| + | |||
| + | A write in this register disables the IPL. | ||
{| class="wikitable" | {| class="wikitable" | ||
| Line 13: | Line 15: | ||
| 7 || Lock Timing | | 7 || Lock Timing | ||
|- | |- | ||
| − | | 6-4 || Timing. 000-001: | + | | 6-4 || Timing. %000-001: ZX 48k; %010: ZX 128k/+2 (Grey); %011: ZX +2A-B/+3e/Next Native; %100: Pentagon. |
|- | |- | ||
| − | | 3 || Reserved | + | | 3 || Reserved, must be 0 |
|- | |- | ||
| − | | 2-0 || Machine type. 000: Config mode; 001: | + | | 2-0 || Machine type. %000: Config mode; %001: ZX 48k; %010: ZX 128k/+2 (Grey); %011: ZX +2A-B/+3e/Next Native; %100: Pentagon. |
|} | |} | ||
Revision as of 19:45, 20 December 2018
| Number | $03 |
|---|---|
| Readable | Yes |
| Writable | Yes |
| Short Description | Identifies timing and machine type. |
Only valid in IPL or config mode (0x0000-0x3FFF are mapped to the RAM instead of the internal ROM).
A write in this register disables the IPL.
| Bit | Function |
|---|---|
| 7 | Lock Timing |
| 6-4 | Timing. %000-001: ZX 48k; %010: ZX 128k/+2 (Grey); %011: ZX +2A-B/+3e/Next Native; %100: Pentagon. |
| 3 | Reserved, must be 0 |
| 2-0 | Machine type. %000: Config mode; %001: ZX 48k; %010: ZX 128k/+2 (Grey); %011: ZX +2A-B/+3e/Next Native; %100: Pentagon. |