Virtual H8 Computer Enhanced Z80 Boards
The default H8 CPU is the I8080. The following propert may override that.
The value of this property should contain a list of featues, separated by
- This specifies the CPU card being used.
The value of the property should begin with "Z80" to specify
modern Z80 boards. The recognized prefix (starts-with) strings are:
- Generic, early, H8 Z80 board.
- Norberto's Z80 board, 64K, etc.
- Norberto's Z180 board.
The following features may be specified:
- TL16C2550 DUART chip, with different interrupt behavior.
- GIDE piggy-back add-on.
- Extended, updatable, 32K ROM (28C256).
Includes EEPROM write-enable and full-ROM-map controls via extended port 0F2H (362Q).
The following devices are always present on Norberto's Z80/Z180 boards:
- Dual serial ports, "con" and "lp" or "aux".
Property "jp4" selects "aux" with value "1".
- VDIP1 USB-storage adapter (includes FT245R here).
- RTC72421 real time clock.
- 64K (1M for Z180) RAM with ORG0 via extended port 0F2H (362Q).
- CPU Speed control via extended port 0F2H (362Q).
The following options (properties) may be selected on Norberto's Z80/Z180 boards:
- Set to "0" to disable the on-board, H89-style, 2mS clock.
Default (if no property) is enable.
- Operate without a front panel. No value is required.
- Enable H89-style NMI for H8 legacy ports.
Intended to be used with "h8_nofp". No value is required.
- Set to "1" to add a modification for a second
on-board 2mS clock enable, in port 0F3H (363Q) bit 1.
Both this bit and port 0F2H (362Q) bit 1 must be set to enable the
on-board H89-style 2mS clock. Defends against accidentally having both
2mS clocks enabled.
Default (if no property) is no mod.