Fits within the same 48 pin socket outline as the original ula. Mp3 and zipped wav audio files are provided along with a link to more information on the game at the world of spectrum web site. Action force 2 ula plus 2 palettes, trainer, music in intro and in game v. The test program exercises all of the spectrum circuitry with the exception of the save function. The ulaplus is a plugin replacement for the zx spectrum ula, and is developed by chris smith see. The lil old zx spectrum 48k service manual supplement no 2. The majority of the new attribute modes can only practically be accessed using machine code but a few can be controlled directly from basic and these are described later in this chapter. Spectrum faq, 301105 since the faq is no longer maintained, for technical details you may want to see the tech info wiki.
The cost of running this website is covered by advertisements. So if both address line a8 and a10 are low, the cpld will output the updown key status of both those rows onto the databus, just like youd see happening with a real spectrum. Congratulations to workshopshed and paulpsomiadis you have been selected as winners of bens zx spectrum portable. Ulaplus is a plugin replacement ula for the zx spectrum which increases the total palette to 260 colours.
How to design a microcomputer zx design retro computer smith, christopher david on. The ulaplus is a plugin replacement for the zx spectrum ula, and is. However, it wasnt until nearly a decade later after the ula was reverse engineered that this actually became possible. So far i have a xc95144xl xilinx cpld hooked up to an issue 4a zx spectrum in place of the ula. Based on the compiler z88dk, the kit allows to develop games and applications in c language. The original ula has been replicated with 100% accuracy in a cpld. The white cassette lead can be seen to the left in the photo below. The zx spectrum had no dedicated sprite generation ics. Ideal for installing in an aftermarket spectrum pcb without needing an original ula. In order to make the z80 processor run faster, a lot of care and some new approaches are required to keep it all working in harmony, in the correct timming. The official home location of the tzx format the current version is v1. The zx spectrum, an 8bit personal computer from sinclair research ltd. As a followup to fridays article on the zx spectrum clone running on the pipistrello, i thought it would be good to share a little more with you on the implementation of the sinclair ula chip.
A gate array is an approach to the design and manufacture of applicationspecific integrated circuits asics using a prefabricated chip with components that are later interconnected into logic devices e. It includes a real z80 and implements a cicleexact ula on a cpld. As the xilinx xc9572xl cpld used in the vla81 had unused resources i decided to. Passes standard ula benchmark tests floatspy, brendans diagnostic rom etc. These all worked as intended which is good news, confirming that the cpld implementation and its dynamic ram interface demonstrates a true 48k zx spectrum ula behaviour. How to design a microcomputer has been completed and the book is with the printer. Oh it quite possible to build a clone around a cpld based ula, i did such a thing, used even less passive components that the original. This was in contrast to other emerging microcomputers of the period, such as the commodore 64.
As the cpld contains no analogue components such as transistors, resistors etc, so a breadboard provides a simple transistor oscillator driven from the spectrum 14mhz crystal which is proving to be particularly unstable, so a dedicated 14mhz clock is also there for comparison, and two output drivers for composite sync and green of the rgb signal. The zx spectrum 16k48k ula went through multiple revisions and is either a 5c or 6c series ferranti ula. The ay38910 is a 40pin package, it contains two general. The heart of the zx spectrum series of computers is a custom chip called the ula uncommitted logic array. The board includes all the zx spectrum standard connections. Allows you to view andor print basic listings from the zx spectrum and since version 0. Zxtunes it is worlds biggest zx spectrum 8bit music collection news musicians software harware interviews podcasts stats forum faq music. Sound from the ay38912 actually a ym2149 core from fpga arcade is mixed in as well. Besides the normal 16colour spectrum screen, it can also produce 64colour ulaplus images. The ay38910 is a 3voice programmable sound generator psg designed by general instrument, also produced under license by yamaha, later also under the microchip technology brand the same silicon chip was sold in three different packages. The spectra interface is a multipurpose peripheral for the 16k48k zx spectrum. The system test for the spectrum may be undertaken using the zxtp taped program loaded conventionally.
Sinclair research ported an enhanced zx80 design to a ula chip for the zx81, and later used a ula in the zx spectrum. The particular model to be synthesised can be selected using vhdl generics. Cpu running at a higher frequency 4 mhz which made it less compatible. The humble48 is a clone of the original sinclair zx spectrum 48k. News f5 to update 20161018 added video retrocod 2016 talk. The problem is that the other components that make a spectrum the ula, for instance, that is responsible for its graphics and other functions were never designed to run faster than 3. Zx81 ulaina cpld not sure where you measure but can be a ground problem at the end. Its primary function is to allow the spectrum to be connected to a tv via a scart socket to produce an rgb picture that is sharp, bright and free from dotcrawl. In the united kingdom and a few other countries it was the most popular games machine of the 1980s, and through the joys of emulation many people are enjoying a nostalgic trip back in time with the games of their childhoods. Zxtunes it is worlds biggest zx spectrum 8bit music collection. The idea was to make a cheap zx spectrum 128k clone with minimum components. The engineering miracle of the sinclair zx spectrum. Designing the divmmc future this is the story of the divmmc future, a version of the divmmc sd card disk drive solution for the zx spectrum, produced by the future was 8 bit. Tool to assist with maintenance of your zx spectrum tapes and zx spectrum emulator tape files.
The zx spectrum is an 8bit personal home computer released in the united kingdom in 1982. The zx spectrum reverse engineering and clone desgin blog harlequin a site dedicated to the reverse engineering of the zx spectrum and related projects. The beeper, present in all versions of the spectrum, is driven by toggling a bit in the ula register in software. Acorn computers used several ula chips in the bbc micro, and later a single ula for the acorn electron. This is an implementation of the complete zx spectrum for the de1 board. For a comprehensive description of how the spectrum generates its tv picture, refer to the zx spectrum ula book 1. I think someone from the team asked if anyone could donate another spectrum or an ula i thought in stepping in and sent my speccys ula on its way to ben. Keyboard options for the zx max 48 zx spectrum clone this is the zx max 48, a sinclair zx spectrum 48k clone by superfo who also designed the harlequin. Thirdly, a design which uses a bodo wenzels custom ula design can be found here spanish. Zx spectrum 128k replica with real z80 cpu and almost all logic in cpld altera epm7128stc100. Scrplus converts images to formats suitable for use with the zx spectrum, using innovative and highly effective algorithms to produce as faithful a rendition of the original image as the limited spectrum palette allows.
Dec 18, 2012 the zx spectrum was launched in april 1982, and by todays standards is a primitive machine. Once proof copies have been checked, distribution will begin. The spectrums z80 cpu and ula would do all the graphical heavy lifting. Next year, from 23rd until 25th of march 2012 the 16th zxteammeeting. The big advantage of this cpld approach is that it can simulate this behavior. Another example of replacing the ula can be found here. The majority of the new attribute modes can only practically be accessed using machine code but a few can be controlled directly from basic and these are described later in. The lil old zx spectrum 48k service manual section 3. This was a technology pioneered by ferranti, of which sinclair was one of the first adopters incorporating all of the discrete logic of the zx80, plus a nmi generation circuit into the initial zx81 2c158e ula.
Simply save a snapshot from your favourite emulator and load it into specprint. Openbench logic sniffer running the zx spectrum ula chip clone. 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. Please scroll down to view the entire site contents. My experience is a diy zx spectrum with real z80 processor, cpld. Pcb designed to fit into original zx spectrum 48k rubber keys case. Jul 30, 2010 the zx spectrum ula is an essential read for the electronics hobbyist, student or electronic engineer wishing to design their own retrostyle microcomputer or anyone with an interest in historical microelectronic and digital design. Games and entertainment software for the zx spectrum.
Using the jsmess emulator, users can boot up an emulation of the given title and use it in their browser. Compatible with zx spectrum standard graphics mode. From the start, this had to be the best divmmc you could buy, had to be small and neat and work on as many spectrums in the range as it could, ideally all of them. The zx spectrum was launched in april 1982, and by todays standards is a primitive machine. Zx spectrum on altera de1 teaser 23 replies last week i was made aware of this post on rs designspark about a project, currently in the very early planning stage, to build a sinclair spectrum on an fpga.
Real z80, rom and ram, and all the logic of the ula in a cpld. Bens zx spectrum portable version 3 created by tariq. Specprint retains all attributes contained in the listing including foreground colour, background colour, bright, flashing1, inverse etc. This one effectively recreates the ula functionality into a modern cpld package complex programmable logic device, which in this cases uses the xilinx xc9572.
Cpld xc95144288xl version, with shared data bus, designed for the harlequin clone. Games for zx spectrum with ula plus, trainer versions. Jan 07, 2018 designing the divmmc future this is the story of the divmmc future, a version of the divmmc sd card disk drive solution for the zx spectrum, produced by the future was 8 bit. If you like it please feel free to a small amount of money to secure the future of this website. The test should be carried out with the spectrum connected to its own power supply. Jul 08, 20 zx spectrum ula chip implementation on obls above. Feedback suggests the same problem affects not more than 1% of zx spectrums that have a 5c112e ula. The value of this bit drives the sign bit of the output to the wolfson audio codec. The sinclair zx spectrum was launched in 1982 by sinclair research limited, as a successor to the sinclair zx80 and sinclair zx81 home computers an 8 bit computer, based on the popular z80 chip which had powered the zx80 and zx81, this introduced colour 8 colours and sound to the home computer market.
Last week i was made aware of this post on rs designspark about a project, currently in the very early planning stage, to build a sinclair spectrum on an fpga. As it happens i have a similar project well under way, and i have promised to write it up several years ago i implemented most of the ula in vhdl on a max7000 cpld, mainly as an exercise to brush up on my hdl. It was designed by myself, phil ruston pcb design, mostly and alessandro dorigatti logic core between 20152016. The cpld version of this implementation is aimed to serve as replacement for that clone.
If youre just getting started with your spectrum and want to test loading software from a pc or audio player, you might like to try some of the old and new games listed below. What is the signal when you take it directly with gnd and vid on your small board as close as possible. Patch files and editors for use with the zx spectrum 64 colour mode. Select an item from the index to be taken to that section. Tested with an extensive suite of zx spectrum software full list to follow. Ulaplus was finally realized in an fpga core by alessandro dorigatti in february 2011. It is anticipated a zx spectrum with a 5c102e ula will not function properly if fitted with this module. The ula or uncommitted logic array is similar in function, but not in implementation to todays cpld s where the work of many ttl logic chips is combined into one ic. The ula uncommitted logic array is a chip which controls most of the interfaces between the z80 cpu and peripheral functions. Several other tests were carried out including floatspy, shock megademo, sidewize and aquaplane. The world of spectrum faq, maintained by arjun nair. Zx spectrum basic tokenizer web site other useful business software goodday is a modern work management platform that brings together the best tools for highlevel planning, project and product management, task organization and productivity growth based on transparency, agility, and motivation. The zx spectrum ula is an essential read for the electronics hobbyist, student or electronic engineer wishing to design their own retrostyle microcomputer or anyone with an interest in historical microelectronic and digital design. Zx spectrum ula plus games the third youth of zx spectrum.
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