1,332
edits
1225: Difference between revisions
Jump to navigation
Jump to search
no edit summary
No edit summary |
No edit summary |
||
| Line 44: | Line 44: | ||
The 1225 is built around a 65C02 as the control processor with 104K of SRAM, and 128K of firmware in a bank of EPROMs. There is a separate board under it that manages the display and keypad, which is powered by another 65C02 CPU. It is using an MC68A45 CRT controller to drive the display. The CRT is a Wells Gardner 7V3030. The display board has 56K of RAM and 8K of ROM. There are two coin cell batteries to retain settings. There is a bug that prevents the 1225 from keeping the date after the year 2000. Upon powering it off and on again it will revert to 19xx, e.g. 2018 will turn into 1918. | The 1225 is built around a 65C02 as the control processor with 104K of SRAM, and 128K of firmware in a bank of EPROMs. There is a separate board under it that manages the display and keypad, which is powered by another 65C02 CPU. It is using an MC68A45 CRT controller to drive the display. The CRT is a Wells Gardner 7V3030. The display board has 56K of RAM and 8K of ROM. There are two coin cell batteries to retain settings. There is a bug that prevents the 1225 from keeping the date after the year 2000. Upon powering it off and on again it will revert to 19xx, e.g. 2018 will turn into 1918. | ||
The keypad switches have a tendency to become very "bouncy". See the page | The keypad switches have a tendency to become very "bouncy". See the page "repairs" tab for details. | ||
===Easter egg=== | ===Easter egg=== | ||