USB Programmer for EPROM 27C, (27C256, 27C512, etc.)

Product Information

Support renew PCF79XX remote, currently support BMW E/F series (Please Note PCF79XX adapter is optional) There is nothing algorithmically complicated about programming one of these – the main difficulty centres on the high Vpp voltage (26V). Most cheap EPROM programms have a max Vpp of 13V. That having been said, there are some cheap programmers which support the 2716 EPROM, also needing a Vpp of 26V, so quite why MCM68766 is such a difficulty, may also depend on other things, such as pin arrangements, or perhaps just limited demand for it. Why is 2708/2704/TMS2716 difficult to program? Some types of EEPROM chips or flash RAM chips can also be used. There is a (bedtime reading) thread about using EEPROMs here. I do recommend having a look at using EEPROMs before considering EPROMs

But there’s a catch with the 28C256: it has something called software data protection (SDP), which protects data from being accidentally overwritten. With the smaller 28C16 (as used by Ben) you can write data in the same way you would with a RAM chip, just by strobing the write pin. You can do the same with the 28C256 if the SDP is disabled, but if it’s enabled then you need to send a specific ‘command sequence’ to the chip. The SDP can be disabled but this requires a similar command sequence 1. To load data you need an EEPROM programmer and like the chips, these devices have become somewhat rare and expensive. Hence the project to build one ourselves. BAW574252, GRM-003, GRM-004, GRM-005, KKZ-06F, MCM2814, PCA8581, PCF8581, PCF8582, PCF8594, PCF8598, PCF85102, PCF85116, SDA2516, SDA2526, SDA2546, X24C00, X24C01 You would need to try and find the original assembler (doing hand coded machine code is very laborious and even more error-prone than assembly); if it was done in machine code, it would need to be re-assembled to make sense of the programme itself. Auto Recognition of File Types We support almost all kinds of known file formats including file formats with automatic recognition functions: Binary, Intel (linear & segmented) Hex, Motorola S, Tektronix (linear & segmented), JEDEC, POF, etc.

Construction & testing

EPROM stands for Erasable-Programmable ROM. The ICs hold code, often an auxiliary program such as an application, utility or game which can be loaded immediately on startup. Sometimes they were used to house the bootstrap code and/or the BASIC interpreter in old microcomputers although this function was often more commonly provided by mask ROMS. Mask ROMS have embedded code that can't be changed. EPROMS also hold code but can be erased and reprogrammed. Once reprogrammed (or "burned"), they can hold their data for many years. Here is an important piece of advice. KNOW THE CORRECT Vpp OF THE EPROM YOU WANT TO BURN. The incorrect voltage can kill it. Chances are your EPROM programmer will require you to select this value. Search Google and get a datasheet for your EXACT EPROM. Not just the size but also the manufacturer. Different manufacturers used different Vpps for their EPROMS. For example, one manufacturer might use 21vpp for their 2716 ICs whereas another may use 25vpp. Make sure you know the specs you're dealing with. Universal 48-pin programmer with USB 2.0 and parallel connectivity. Dataman 48UXP features intelligent hardware, including microprocessor and FPGA, allowing it to program devices you use today and the devices of tomorrow... Ben’s design permanently connects /CE to ground and drives /OE via one of the 74HC595 shift registers. To get this to work we need be able to drive all three of the EEPROMs control lines. I’m also going to move /WE away from pin 13 of the Arduino. This is also the pin driving the on board LED and I’d rather use that for status information without risking corrupting the EEPROM. For now, just remove the wire between the ‘595 and /OE (the rightmost white wire in the photo above). Comparing the pinouts for the 28C16 and 28C256 shows that they both have pretty similar layouts. On the left hand side of the chip everything is the same just with the new pins 1 and 2 added (A14 and A12). On the right hand side we need to move Vcc to the new pin 28 and add A13 and A11 to replace the it and /WE. 28C16 pinout 28C256 pinout

These EPROMs are NOT in mission-critical equipment. And although I used to regularly do this for customers oh, so many years ago, I want to give the customer the best chance these chips will work correctly for the indefinite future. Super fast industrial gang programmer with four independent modules, ISP capabilities and USB 2.0 connectivity. The 448Pro2AP is built to meet the demands of high volume production programming with automated handlers and ATE machines... I had a Willem but it died so my current programmer is a Top 853 out of China (fig 3). It's also inexpensive, is completely software driven and can supply all necessary programming voltages from a USB link. It seems to work well, although at the time of writing the manual for this Chinese device appears to have been written using an early version of Google Translator! It's almost completely unreadable. If you know the basics though the software is easy enough to follow. Getting to grips with EPROM programming, and having the gear to do it, is worthwhile if you want to maintain a vintage computer collection. As well as being able to replace faulty masked ROMS and EPROMS, you can also READ the ROM contents of rare machines. Not all ROM images are available on the Web and it's a good idea to extract the code for posterity (and possible future use!).And yes, programmers use a DC-DC inverter to get the high programming voltage (be it 12V, 12.5V, 13V, 13.5V, 21V or 25V). If there is a problem with the DC-DC inverter, none of the EPROM cells will be programmed properly, or maybe just the first handful will be and then the rest will fail to be programmed properly. the SEEprog programmer is NOT INTENDED to be a ISP programmer. If you think about ISP, use please the programmers, equipped by ISP connector ( SmartProg2, BeeProg+, ...) MC9S12D64, MC9S12A128, MC9S12DG128, MC9S12DG256, MC9S12H128, MC9S12H256, MC9S12HZ64, MC9S12HZ128, MC9S12HZ256 However, there are some important differences between standard EEPROM ICs sold as computer or microcontroller chips, and other popular memory types - including flash storage.

EEPROMs can be a bit temperamental, especially with fake chips around. Different brands can behave slightly differently, so what works for me with my setup may not work for others. There are two important voltages applied to EPROMS. One is the READ voltage. This is applied to the Vcc pin and is typically 5 volts. It is used to read the data in the EPROM. The other voltage is the programming voltage (Vpp). This is used to burn data in the EPROM and can vary depending on chip type and manufacturer. Typical values are 25v, 21v or 12.5v.

Specifications

RetroSix is a small team of people who have been in the gaming industry and retail business since 2013, and sold consoles, controllers and even designed our own controllers and consoles. I found that that this design was /very/ unstable until I added some decoupling capacitors (0.1uF). You can find mine next to the power pin for teh EEPROM, the ground pin for the EEPROM and the power pin from the Arduino. Three capacitors is probably overkill but it took me a lot of debigging before I realised I needed them. The upgraded BenPrommer with 28C256 EEPROM Schematic for the upgraded BenPrommer Software Changes Mike, your intro nails my situation. I’ve built Ben’s 8-bit computer and am working on an expanded version using AT28C256 chips. I only stumbled onto SDP a couple of days ago by using a TL866ii Plus programmer, experimenting with the EEPROM I so far could not write to, and then later was able to write to the chip using Ben’s programmer (already modified to fit the AT28C256). My brisk research turned up a number of references but yours stood out. However, I’ve now made the HW changes and have tried to get your code to work with it but nothing I’ve tried seems to result in disabling SDP, including adding capacitors to my board. Additionally, when I ran your code as is, I was able to discover that without manipulating /CE, a read after write was actually always returning the value that had last been written, and, in fact, nothing had been written to the EEPROM. This was verified by making sure /CE was low when reading and the actual contents of the EEPROM were returned. Have you been able to verify the contents of your one AT28C256 separately from your sketch code? On the other hand if you DID actually get it to work, I’m curious as to what I am overlooking and would welcome any additional insights you may have. NOTE: Although I do have a separate EEPROM programmer, I really want to get the BenEater version working for this. The software that comes with the programmer will manage the burning process. Modern programmers use menu-based interfaces that are easy to use. With the chip in place, the first step is to load the code into a buffer prior to burning it into the EPROM. Code for ROMS and EPROMS can be found on the Internet for all kinds of vintage computer models. The code needs to be a binary file. Figure 4 shows a screen shot of my programmer with a 4k System 80 ROM image loaded.