Spectrum QL
Contents
Spectrum QL
The Sinclair QL (for Quantum Leap) is a personal computer launched by Sinclair Research in 1984, as an upper-end counterpart to the ZX Spectrum. It was aimed at the serious home user and professional and executive users markets from small to medium-sized businesses and higher educational establishments, but failed to achieve commercial success. The Sinclair QL uses a Motorola 68008.CPU with 32-bit internal data registers, but an 8-bit external data bus.
Setting up
- Assembler: VASM
- Emulator(s): Q-emulator ( http://www.terdina.net/ql/winql.html )
- Hardware:
In order to test the final result one can use a floppy-disk replace replacement or Qubide interface to load files from SD card.
Memory map
$00000 Onboard 48k Rom
$0C000 16K Rom Cartridge
$10000 Onboard I/O
$18000 (R) RTC byte 0 / (W) RTC Reset
$18001 (R) RTC byte 1 / (W) RTC Step
$18002 (R) RTC byte 2 / (W) Transmit control
$18003 (R) RTC byte 3 / (W) IPC link control
$18020 (R) Microdrive/RS232c status / (W) Microdrive control
$18021 (R) Interrupt/IPC status / (W) Interrupt control
$18022 (R) Microdrive Track 1 / (W) Microdrive / RS232C data
$18023 (R) Microdrive Track 2 / (W) Display control
$18063 Screen Mode S---C-O- On Colordepth Screenpage
$20000 Screen 1 Screen Ram
$28000 Screen 2 /
System system (systemvars*)
$2847C System stack pointer*
$28E00 Base of Common Heap*
$2BC00 Free area*
$30000 Running Programs Free area
$37200 Basic area*
$38000 User Stack pointer*
$38000 Prog data*
$40000 Add on ram (up to 512k)
$C0000 Add on peripherals
$E0000 Add on Rom (up to 128k)
$FFFFF End of address spaceVideo display
There are two possible screen modes, configured by bit 3 of port $18063
setting a 0 give 4 colors at 512x256 with Black,Red,Green and White setting a 1 give 8 colors at 256x256 with Black, R, G B, C, M, Y and White
The Screen is memory mapped from $20000-$28000, There is no palette - the colors are fixed.
Vsync
Port $18021 bit 3 will go high (1) when Vsync starts, then we need to write a 1 to that same bit at the same port to clear the Vsync event. Therefore, in effect we can write 255 to port $18021, then read from $18021 until it's nonzero to get the Vsync event.
move.b #%11111111, $18021 ; Clear interrupt bits
waitvbl:
move.b $18021,d0 ; Read in interrupt state
tst.b d0 ; Wait for an interrupt
beq waitvblPlotting to screen
To be addedSound
The Spectrum QL has 2 channels of internal beeped sound, or AY support via the
