DMA interface for ZX Spectrum

[KingOfEvil]

This is DMA interface for ZX Spectrum. On board is used Z80-DMA and one GAL as port decoder. Schematic is compatible with DMA in MB02 interface.

http://velesoft.speccy.cz/data-gear.htm

Can you describe this device in English? It's very difficult for me to understand Czech text.

[Advertiser]

[VELESOFT]

Can you describe this device in English? It's very difficult for me to understand Czech text.

O.K. This is standard Z80-DMA and is possible buy old versions UA858D or original new DMA from ZILOG.
http://www.zilog.com/download/defaul...1886&from=onyx

DATA-GEAR is DMA part from MB02+ schematic (100 % compatible with DMA chip in MB02 diskdrive: http://www.8bc.com/sinclair/

DMA use port 23(dec) for programming. Clock for DMA is connect to CLK signal from Z80CPU. Maximum speed of data transfer is 1byte / 4T cpu (2T for read source byte + 2T for write byte). Z80 DMA support more transfer modes:
- memory to memory
- memory to port
- port to memory
- port to port
Source or target adress can be inc(dec)remented or fixed.
Is possible use different speed for read and write (2 - 4T).

For test you can play any games or demos with DMA support.
Emulator REALSPECTRUM( + ZX128 mode + MB02) is compatible with
DATA-GEAR (= MB02 without memory and FDD ).

Example of DMA transfer (fullscreen scroll 50fps - green border is DMA transfer )
http://velesoft.speccy.cz/data-gear/dma-scr-rol.avi

[KingOfEvil]

O.K. This is standard Z80-DMA and is possible buy old versions UA858D or original new DMA from ZILOG.
http://www.zilog.com/download/defaul...1886&from=onyx

DATA-GEAR is DMA part from MB02+ schematic (100 % compatible with DMA chip in MB02 diskdrive: http://www.8bc.com/sinclair/

DMA use port 23(dec) for programming. Clock for DMA is connect to CLK signal from Z80CPU. Maximum speed of data transfer is 1byte / 4T cpu (2T for read source byte + 2T for write byte). Z80 DMA support more transfer modes:
- memory to memory
- memory to port
- port to memory
- port to port
Source or target adress can be inc(dec)remented or fixed.
Is possible use different speed for read and write (2 - 4T).

For test you can play any games or demos with DMA support.
Emulator REALSPECTRUM( + ZX128 mode + MB02) is compatible with
DATA-GEAR (= MB02 without memory and FDD ).

Example of DMA transfer (fullscreen scroll 50fps - green border is DMA transfer )

Thanks.