The module’s video output is the same as that provided by the original ULA (IE: YUV to drive the Spectrum’s modulator circuit. The +2A and +3 both use the same 40077 gate array. It is one of several ULA replacements I have made for members of the Sinclair computer family including the vLA81 for the ZX81, the vLA128 for the Spectrum 128K (Toastrack) and +2 (Grey case) and the vLA1 for the Sinclair ZX Interface 1. This is a replacement for the ULA in the Sinclair ZX Spectrum 128 toastrack and Sinclair ZX Spectrum+2 (grey case). The Gameduino has footprints to solder either a 512KB SRAM memory, or a 32MB SDRAM. Despite their different designations, they are functionally identical. However, there is certainly something wrong with Z80 access to the lower 16K RAM or ROM as the video memory has not been written to with the usual ©1982 Sinclair Research Ltd message. 5C102E – Issue 1 and 2 PCB’s (requires cockroach mod). The aim of the site is to allow the renewal of retro computers, whilst not making a huge profit. See xilinx/ directory for design examples. Real matrix keyboard version. CPLD (XC95144/288XL) version, with shared data bus, designed for the Harlequin clone. Fits within the same 40 pin DIL socket outline as the original ULA. Yet to be tested against a real Z80 for timming accuracy (tv80 core seems not to have exact timmings, but this could be my fault, not tv80's). At the end of the day, we’re just hobbyists). Digital IRGB output, PAL timmings. This ULA also incorporates a change to the internal pull up resistors which causes the EAR bit value to float between 0 and 1 until the ULA has warmed up, instead of persisting at logic 1 like the 5C series. Emulation aims to be cycle perfect – it passes the FUSE tests and runs programs that rely on the floating bus behaviour. Tested with an extensive suite of Spectrum 128/+2 (Grey) software. vLA82, vLA128 The Nebula is a plug-in PCB module designed to replace the ULA chip found in UK Spectrum 16/48 motherboards (versions 2 to 6) - You can read more about it here. Part II. Also, please read these important fitting notes. Naturally the best picture is obtained when the Spectrum has been composite modded but RF still works). This worked as expected and so the CPLD was hooked into the Spectrum, as shown above. More information on the Spectrum ULA can be found in Chris Smith’s excellent book, “The ZX Spectrum ULA: How to Design a Microcomputer” (Amazon search link). A new enhanced ULA description which supports this mode has been uploaded to the fpga_version directory. Tested with an extensive suite of ZX81 software. ZX Spectrum design in a Digilent Spartan 3 Starter Board. Nebula Spectrum ULA Chip Replacement Module The Nebula is a Spectrum 48 daughterboard, designed to replace the ULA chip found in UK Spectrum motherboards (versions 2 to 6). ZX Spectrum clone built around an earler version of the ULA design. A drop in replacement for the 6C001E-7 and earlier ULA’s (vLA82, 48K machines), and for the 7K010E-5 and Amstrad 40056 ULA’s (vLA128, 128K machines). The Gioconda, displayed in the ULA+ & Time HiColor enabled clone. It is one of several ULA replacements I have made for members of the Sinclair computer family including the vLA82 for the Spectrum 48K, the vLA128 for the Spectrum 128K (Toastrack) and +2 (Grey case) and the vLA1 for the Sinclair ZX Interface 1. If you have a product or service that you would like to make available to the community please do not hesitate to get in touch. The vLA81 is a modern plugin replacement for the ZX81 ULA. “I´ve attached Photo of 48k ULA FERRANTI ULA 6C001E-7 8447 which I can´t find on yet your „ZX Spectrum ULA gallery“. Replicating the functionality has proved tricky due to the use by Sinclair of ULA peripheral cells to provide analogue functionality (YUV output, tape interface etc). Designed by Charlie Ingley, these will shortly be available via SellMyRetro.com. It suffered from a buggy I/O contention model which made I/O reads, particularly keyboard reads from machine code, unreliable, hence the addition of the ‘cockroach’ mod (basically a 74LS00 chip hand soldered on top of the PCB with flying lead connections, later contained on its own mini daughterboard). Dark Star. 5C112E, 5C112E-2, 5C112E-3 ULA This part is very sensitive to interrupt, ULA and Z80 timmings, so it's a perfect test. Fitting: On rubber key Spectrums, space between the ULA socket and top cover is extremely limited. This is an implementation of the Sinclair ULA chip, found in ZX Spectrum microcomputers. The same clone, now using a proper RGB output. The ZX Spectrum Issue 4A and above will ONLY work reliable with the 6C001E-7 ULA version; don’t use another ULA in an Issue 4A board or later Issue.