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Migration to NemoBus ideology[B][U]Migration to NemoBus ideology.[/U][/B] Unfortunately all modern western hardware design is based on an outdated ideology bus, which was establ…
[QUOTE=Black_Cat;665901]The idea of blocking the address A15 is not good. For this purpose there are signals MREQ/ and ROMCS/.[/QUOTE]
Blocking A15 is considerably more tolerant of propagation delays than blocking MREQ. -
INTERFACE 2 - light versionSmall interface (adapter) compatible with INTERFACE 2. Contain only slot for IF2 cartridges and reset button (for rubber speccy). Not contain joystic…
[QUOTE=mcleod_ideafix;666365]Is it compatible with Spectrum +2A/+3?[/QUOTE]
No. Use only classic ROMCS then is unusable with +2A/+3 models. But I can add switch for compatibility with +2A/+3 -
ZX Eprom replacing Rom problemsI got a programmer today so I could finally flash the Xicor X28C256 eproms I have with ZX128 rom, to be used in my upgraded 48K machine. But for some…
... is connected to MREQ and ROMCS and then connected to pin ... works without problems.
ROMCS ---> or Gate 74LS32
The new Superfo cloneHi In the spanish forum speccy.org some guys and me have optimized the superfo clon to have less ICs. The actual design has 39 ICs versus the 45 ICs…
... uses the !CE pin for ROMCS unlike the +3 which uses ...Another cause for DivIDE problems on 48K'sThe last months some topics were opened to discuss problems with 48K ZX Spectrums and DivIDE. Sofar we found: - Bad Z80's because of poor fanout (si…
Another cause for DivIDE problems on 48K'sThe last months some topics were opened to discuss problems with 48K ZX Spectrums and DivIDE. Sofar we found: - Bad Z80's because of poor fanout (si…
... is responsible for generating the ROMCS signal.
With a ... main difference between the way ROMCS is pulled high on DivIDE ...Another cause for DivIDE problems on 48K'sThe last months some topics were opened to discuss problems with 48K ZX Spectrums and DivIDE. Sofar we found: - Bad Z80's because of poor fanout (si…
Another cause for DivIDE problems on 48K'sThe last months some topics were opened to discuss problems with 48K ZX Spectrums and DivIDE. Sofar we found: - Bad Z80's because of poor fanout (si…
... ://www.circuitlab.com/circuit/c27qgp/romcs-handler-comparison/][img]https://www ... option seems to not pull ROMCS high enough, and sometimes, low ...Another cause for DivIDE problems on 48K'sThe last months some topics were opened to discuss problems with 48K ZX Spectrums and DivIDE. Sofar we found: - Bad Z80's because of poor fanout (si…
... ://www.circuitlab.com/circuit/c27qgp/romcs-handler-comparison/][img]https://www ... option seems to not pull ROMCS high enough, and sometimes, low ...Another cause for DivIDE problems on 48K'sThe last months some topics were opened to discuss problems with 48K ZX Spectrums and DivIDE. Sofar we found: - Bad Z80's because of poor fanout (si…
... ://www.circuitlab.com/circuit/48e7f5/romcs-handler-comparison-schottky-fix-for ... me a spike everytime the ROMCS signal went high to low ...Another cause for DivIDE problems on 48K'sThe last months some topics were opened to discuss problems with 48K ZX Spectrums and DivIDE. Sofar we found: - Bad Z80's because of poor fanout (si…
What is the reason to drive ROMCS line with transistor, is signal from gate too slow ?Another cause for DivIDE problems on 48K'sThe last months some topics were opened to discuss problems with 48K ZX Spectrums and DivIDE. Sofar we found: - Bad Z80's because of poor fanout (si…
... chip (CS input). So, ROMCS is a direct connection to ... that signal with one from ROMCS (rear slot). This signal ... generated by ULA_ROMCS. When ROMCS is 1, the ROM ... is off and the ROMCS pin is at high ... the BJT cannot drive the ROMCS signal strong enough, due to ...The new Superfo cloneHi In the spanish forum speccy.org some guys and me have optimized the superfo clon to have less ICs. The actual design has 39 ICs versus the 45 ICs…
... br /> #7B/123 xxxxxxxx01111011 xxxxxxxx0xxxx0xx ROMCS-off /STROBE
#FB/251 ... - DATA(/TxD)
00xxxxxx1xxxx0xx ROMCS-on,BUSY,DSR -
...How far are we from a single-chip 100% ZX Spectrum compatible solution?I really like to read about the projects of some geniusses here on WoS who are working on their ZX Spectrum clones. IMHO some main steps that have b…
... ,WAIT,RESET,BUSACK,BUSREQ,REFRESH,ROMCS,INT,NMI,HALT,CLK = 39 ...How far are we from a single-chip 100% ZX Spectrum compatible solution?I really like to read about the projects of some geniusses here on WoS who are working on their ZX Spectrum clones. IMHO some main steps that have b…
... ,WAIT,RESET,BUSACK,BUSREQ,REFRESH,ROMCS,INT,NMI,HALT,CLK = 39 ...The new Superfo cloneHi In the spanish forum speccy.org some guys and me have optimized the superfo clon to have less ICs. The actual design has 39 ICs versus the 45 ICs…
... for future)
3) external ROMCS in log.1 can inhibit ... 3 : if external device disable ROMCS then must be internal CF ... . ( use 74HC74, SET input = external ROMCS in log.1 ). You must ... detect only external ROMCS state (if internal romcs from ula is ...SPECTRA New from Paul FarrowLooks good! Read about it [URL="http://www.fruitcake.plus.com/Sinclair/Spectrum/Spectra/SpectraInterface.htm"]here[/URL]
... the divIDE+ should monitor the /ROMCS line on its expansion bus ...Another cause for DivIDE problems on 48K'sThe last months some topics were opened to discuss problems with 48K ZX Spectrums and DivIDE. Sofar we found: - Bad Z80's because of poor fanout (si…
... has to be disabled, the ROMCS output of the GAL is ...Another cause for DivIDE problems on 48K'sThe last months some topics were opened to discuss problems with 48K ZX Spectrums and DivIDE. Sofar we found: - Bad Z80's because of poor fanout (si…
... has to be disabled, the ROMCS output of the GAL is ...Another cause for DivIDE problems on 48K'sThe last months some topics were opened to discuss problems with 48K ZX Spectrums and DivIDE. Sofar we found: - Bad Z80's because of poor fanout (si…
... .... and we need additional logic... ROMCS can be connect direct to ...Another cause for DivIDE problems on 48K'sThe last months some topics were opened to discuss problems with 48K ZX Spectrums and DivIDE. Sofar we found: - Bad Z80's because of poor fanout (si…
... .... and we need additional logic... ROMCS can be connect direct to ...The Disciple clone... doable?Hi. As a spectrum user in the 80's this was the dream interface all-in-one for me. I have a 48k+ and planning on get a 128K toast-rack later. Anyway…
... we never got its paging (ROMCS handling, most likely) working under ...The Disciple clone... doable?Hi. As a spectrum user in the 80's this was the dream interface all-in-one for me. I have a 48k+ and planning on get a 128K toast-rack later. Anyway…
... lines work (mainly /M1, /MREQ, /ROMCS, /IORQ, /RD and /WR, /INT ...The Disciple clone... doable?Hi. As a spectrum user in the 80's this was the dream interface all-in-one for me. I have a 48k+ and planning on get a 128K toast-rack later. Anyway…
Getting PC into HLHello, here's a conundrum for you... Is there a way to obtain the value of the PC register (say into HL) without using absolute addressing such as C…
[QUOTE=Dr BEEP;683262]What's wrong with the CALL to ROM?[/quote]
Something might have asserted /ROMCS.Getting PC into HLHello, here's a conundrum for you... Is there a way to obtain the value of the PC register (say into HL) without using absolute addressing such as C…
[QUOTE=Philip Kendall;683268]Something might have asserted /ROMCS.[/QUOTE]
True!PlusD Mini: implementing the CPLDI am doing my first attempts on creating a CPLD to use as replacement for the PlusD's GAL (and other logic lateron). I use the Xilinx XC9500XL series…
... use RESET, but do control ROMCS.
And as the ... the CPLD drives the ZXs ROMCS?
I have ...PlusD Mini: implementing the CPLDI am doing my first attempts on creating a CPLD to use as replacement for the PlusD's GAL (and other logic lateron). I use the Xilinx XC9500XL series…
Well, one thing is clear: ROMCS is definitely getting asserted OK ( ... paged out, showing that the ROMCS circuit is managing to prevent ... getting selected, which is what ROMCS is there to do). Whether ...The Disciple clone... doable?Hi. As a spectrum user in the 80's this was the dream interface all-in-one for me. I have a 48k+ and planning on get a 128K toast-rack later. Anyway…
... of the 128K, especially concerning ROMCS. My understanding is that 'ROM ... at first, and handling of ROMCS is independent of whether ROM ...
