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ZX PC InterfaceZX <-> PC Interface Contents 1) The ZX <-> PC Interface 1.1) What is it? 1.2) What does it do? 2) Installation 2.1) The softwa…
... to 5V and also to /ROMCS. This is used to switch ... -
Disable onboard memoryWould this work...? Access to onboard I/O can be disabled by holding IORQGE high. Would it be possible to create a MEMRQGE in a similar way to disa…
... disable all onboard memory - like ROMCS but for the whole memory ... -
A vexatious questionThis is kind of a follow-up to a question about RST #8 and hardware that I wrote in the development forum a while ago. To summarize that: certain ha…
... check the state of ROMCS before nailing the signal ... first device to nail ROMCS. The other device just ... checking and then hold ROMCS high, so the two ... daisy chain, that is, ROMCS passes through some logic ... way of handling the ROMCS line so that two peripherals ... -
It's a trap!So I got a CPLD (not the eventual one I want to use for the ethernet project - rather, one I actually have here and now, an XC9536 in a PLCC44). And…
... interest active, I immediately grab ROMCS, and hold A15 high. ... prevent the brief glitch (on ROMCS/A15OUT) that would otherwise occur ... MREQ went low before grabbing ROMCS and asserting A15OUT high ( ... an instruction fetch, the ROMCS/A15OUT latch isn't released ... -
Faulty M1 pin on a Z80 made from SGS?It's the second time I have come across this: a Spectrum that seems to work ok, but if I attach an Interface 1 or a DivIDE to it, it behaves as is no…
... , so I cannot blame on ROMCS pin.
The logic ... others, of course) to raise ROMCS and let the interface to ... -
Schematic error.. (?)Hi, I was browsing this page: [URL="http://microhobby.speccy.cz/150203/hardware/bus.html"]http://microhobby.speccy.cz/150203/hardware/bus.html[/URL]…
... on the pin of the ROMCS (25B) but on the picture ... -
winston's diagnostics boardHi Winston, I've recently built your diagnostics board on project board and am having huge problems getting it running. I've been pulling my hair ou…
... and moved the reset and romcs as per the pinout. ... without romcs connected, the board does ... LED's, but with ROMCS connected the speccy will not ... mad. seems like the ROMCS signal is jumping all over ... 2N3802 fets to drive the ROMCS line. Do you know ... -
winston's diagnostics boardHi there Mr Winston I don't know if you remember I posted about your diagnostics board earlier and how i used a 7404 instead of the 2 mosfets, well I…
... using a mosfet on the ROMCS line I used a 2N3906 ... couple of diodes on the ROMCS lines and hitting the two ... -
DIVIDE PLUS - ZX bus protectorI make new ZX BUS PROTECTOR for use with DIVIDE PLUS interface. This is very small "convertor" for connection to new ZX BUS connector. PCB contain on…
... use external memory)
- ROMCS and both ROMOE signals on ... -
Shadow ROM partial decoding not implemented in emulatorsOr at least, not implemented in Spectaculator, and it seems that not in Fuse too. [URL="http://www.speccy.org/foro/viewtopic.php?f=8&t=408&start=53"…
... , because as he argumented, the ROMCS line doesn't page off ... -
Switching peripherals on and offis there a way in which i can add a switch to switch off peripherals and switch another one on i.e. Multiface, DivIDE etc? Can i add it on the NMI o…
... it on the NMI or ROMCS lines on a 48k Spectrum ... as they dont have a ROMCS line.
i dont want ... -
ROM switch on NMIHello! Please, help me or point in the right direction. I am building a project for 48k spectrum which must activate its rom (actually static ram) …
... M1 starts i can switch ROMCS
and deactivate my NMI ... . So, this way ROMCS switch in between instruction fetches ... /> The problem here is that ROMCS must be changed very fast ... ,
wait for BUSACK, change ROMCS, deactivate BUSREQ, wait for M1 ... -
Stealth AllRAM SpectrumHaving just received a couple of new keyboard membranes to fix a couple of machines with, the thought crossed me that I should do a special project w…
... , the ROM itself combines the /ROMCS and /MREQ signals to form ... /MREQ must be combined externally. (/ROMCS is generated by the ULA ... must be generated by combining /ROMCS and /MREQ. This is done ... other words the product of /ROMCS + /MREQ.
4. Solder ... -
ZX Breakout availabilityOK - after much procrastination, this board is now available! Details on the board are here: - [url]http://spectrum.alioth.net/doc/index.php/ZX_Bre…
... ), a 3.3v regulator and ROMCS mechanism.
[b]Errata ... cockup on my behalf, the ROMCS circuit is wrong for the ... . If you don't need ROMCS on a +3, then just ... 've not tested anything. The ROMCS circuit works fine with a ... -
Diag rom works cartridge on +2A/+2B/+3I'm not sure anyone has tested this before: using the diag rom (Paul Farrows) on a +2A/+2B/+3. I had a +2A with a problem, so I wanted to use the di…
... laying around, which put the /ROMCS signal on both /ROM1 and ... -
ROM replacement using 28C256 EEPROMThought I'd share a quick project I knocked up in order to use a 28C256 EEPROM in place of the standard 23128 ROM in the Spectrum. The connections a…
... gate to combine /MREQ and /ROMCS, which I then feed to ... -
edge connector... breadboard / external romso i purchased a breadboard on a edge connector.. to experiment with .. my first task to make a external rom boot (32k eeprom) so i think i got every…
... : A13 - A0 : 5 volt to romcs to disable onboard rom : using ... -
Interface 1 ULAIs there a technical description of the functionality of the Interface 1 ULA, similar to the "The ZX Spectrum ULA" book? Specifically, what is the…
... is the difference between the ROMCS and the ROMEN lines of ... the ULA? Superficially, ROMCS feeds into the Spectrum to ... . And in what cases would ROMCS and ROMEN not be both ... -
Hardware specialists ?????Are there any Sinclair hardware specialist around here? I think most of you are more gamers and I need a hardware specialist for some questions!!!!
... 16K RAM (also adressed by ROMCS) and program an emulator which ... -
Spectrum edge connectors and 'Dataman Softy S4'Hi, I moved this from the sales thread because it seems more appropriate...anyway... I was twerping around the idea of turning a Spectrum into a we…
... this is to assert the /ROMCS signal at power up and ... /> - don't assert /ROMCS at power up. Attach /ROMCS to an i ... code loading.
- assert /ROMCS at power up to swap ... you'll have to deassert /ROMCS and join the Spectrum ROM ... -
Spectrum edge connectors and 'Dataman Softy S4'Hi, I moved this from the sales thread because it seems more appropriate...anyway... I was twerping around the idea of turning a Spectrum into a we…
... quote]
Almost right. /ROMCS is active low, so you ... art:
_C____ /ROMCS
|/
C2 ------RRRR ... with C2 high, causing /ROMCS to go low. When ... xtor is off, letting /ROMCS be pulled high by a ... -
Spectrum edge connectors and 'Dataman Softy S4'Hi, I moved this from the sales thread because it seems more appropriate...anyway... I was twerping around the idea of turning a Spectrum into a we…
... internal memory. The Spectrum's /ROMCS is the actual active low ... -
Programing ROM CART from PCHave anybody tried to make a piece of hardware that would be able to program (burn) SINCLAIR cartridge from PC? In the sense, you take TAP or TZX and…
... 16 K ROM (with the ROMCS line). More memory will make ... -
Programing ROM CART from PCHave anybody tried to make a piece of hardware that would be able to program (burn) SINCLAIR cartridge from PC? In the sense, you take TAP or TZX and…
... 16 K ROM (with the ROMCS line). More memory will make ... -
I want to spice up my Speccies. RecommendationsOK, since I got more speccies than I ever wanted (ok, there's never enough old computers in here :D), I want to upgrade some of them. Here are my mac…
I don't alter the original machine, but would add a simple EPROM-interface at the back. I did it for my ZX-PC Interface and it works perfectly. For the +3 however you need to select another pin then /ROMCS to activate your EPROM. -
Ecstasy & AgonyWhile checking out the area around Chennai Central station on Sunday, I came across this crowded narrow road taken up entirely by roadside vendors se…
... on the R/-W line, ROMCS, NMI etc etc but now ... -
AmericaI've been wondering, was the Spectrum released in America? Was it popular? Are there Spectrum games that were made in America? There must be a few A…
... memory. The 48k Spectrum had ROMCS which allowed the first 16k ... -
rom switchhow could one go about building a rom switch, to switch between +3 roms and +3e roms.
On my ZX-PC Interface I have an EPROM.
It runs on all 128K.
On a +3 you need to point to another ROM-select signal than ROMCS. Eprom is activated when +5v on ROMCS (in the middle under, not 4th from edge under)
