C64 EPROM PROGRAMMER (DELA EPROMMER II - REDRAWN)

The internet was not available at the time this EPROM programmer was designed. Nowadays, there are C64 ROM files in many formats on the internet. If you know how to convert ROM files in these different formats to the appropriate form, the answer will be yes, but this is a job that only highly knowledgeable people can do. As long as you choose the correct parameters in the software, copying from EPROM to EPROM will not be a problem.

Allow me to clarify: I am not talking about the various formats of CRT ROM files available on the Internet today. I understand those have various headers for use in emulators, etc. I am simply talking about plain old BIN files, which contain nothing other than the bytes that should be programmed to the EPROM, in consecutive order. (These also existed in the C64/128 days; in fact some of the C128 option ROMs were distributed on floppy disk as shareware, for users to program into their own 27256 EPROMs.) The only format difference, of course, would be the 2-byte PRG load header. In my mind, I should be able to download a BIN file for an EPROM (from Zimmers, for example), prepend a 2-byte load address to load it to the correct place in RAM on my C64, and then use this device to program a ROM chip. I am asking if anyone has successfully done that, because Giovanni giobbi suggests in his posts that this will produce a scrambled ROM; he seems to say that his devices do not program all the bytes consecutively from RAM to ROM, but instead expect the input data to be in its own special scrambled format. If that's the case, then the device is only useful for copying existing EPROMs, and not useful for programming new ones. I am looking for anyone else who has built this project to confirm or refute his experience. Thanks for your attention!

I have programmed many eproms with this programmer. I used original Dela Epromer ii software,.this softwre loads and saves binary files starting from $1000 , so you need to add HEX " 00 10 " first two bytes at the starting of pure binary file. Then you need to save this file to a 5.25 inch commodore formetted diskette. Please read the link below for some details. In order to be able to do these jobs, you need to be familiar with the Commodore 64 cartridge system, for example, for a standard 8/16KB game cartridge, the expression_ "CBM80" must be in exactly the right place. If there is no hardware fault in your Commodore 64 or your eprom programmer, there is no encryption.

https://www.pcbway.com/project/shareproject/C64_4x16KB_I_O1_AUTOMATIC_SHUT_OFF_CARTRIDGE.html

"If I compare the EPROM with the memory content at $1000, most time it seems to be the same, but when I get the save PRG from the disk, remove the two first bytes (loading address) and compare it with the original BIN, the content is all scrambled / different. " This is normal. they should not be the same. For testing; read data from one eprom and then write the same data to another eprom. If the second eprom works, it's fine.

Unfortunately the content of the second EPROM is scrambled too. Weird fact: I chatted about that with another guy that owns a couple of original DELA eprommer (not a replica). He did some tests and told me it has the same trouble using 27256 EPROMs. So, maybe, it's a fault of the original project.

BTW he also told me that CP3 is a 63v capacitor in the original board; he measured 49v at the CP3 pins. However I tried to replace CP3 with a 100 uF - 100v, but it didn't solve the issue.

Can you test the 4040 , 7406 and 74LS373 chips? Sometimes the problem may be with the CIA(6526) chips. With this programmer, I was able to program 27c256 eproms many times without any problems.

Honestly I don't know what's going on... I've built three different units just to be sure there weren't some flaws in the assembly. I tested all the 74xx ICs with my MiniPro programmer and also I replaced them with other ones from different brands/lots/sellers. I can't test the 4040 but I bought and replaced them with other ones from another seller. I tried with three different C=64. I tested all the C=64 with the Dead Test cartridge that makes some basic tests on the 6526 and I also swapped the two 6526. I don't understand what's wrong, I ran out of ideas... I think I will give up on that :-(

OK I will try it.

Thanks for asking. Please try 100μF 35V or 50V. And the original Commodore 64 power supply must be used.

just tried a 50 Volt. Heats up a bit but seems to be working. Not near as hot as the 25V. Thanks for your help!

You're welcome

Now If I can just figure out the instructions. :)

1 - Blank test, 2-Read eprom, 3-Programm eprom, 4-Repeat programming, 5-Compare eprom with memory 6-Menu 2. I hope you like it. :)

David, did you tested 2716 and/or 2732? Also, did you try to get some BIN from the web, just slap the 00 10 address at the beginning of the BIN file and use it to program an EPROM?

Hello giobbi, - It can program BIN images (as you can download from Zimmers' site) by reading from disk, but in c64 file system the first 2 bytes are the loading header bytes, you will need to pay attention to this. As far as I know, there is no English version of the program or an English user manual. Thank you for asking. Thank you!

do you mean that it loads the BIN in the C=64 RAM, in example starting from $9000, but when you program the EPROM must to tell to read starting from $9003, or do you mean something different? Since you're using this programmer and surely know how it works, can't you write a brief tutorial (just few lines) to give us a starting point? Cheers,

I am also interested in this. How to record CRT/BIN to floppy/tape,and then load it to custom RAM location? Did you try to translate manual from german via google translate? Or is there any german native speakers here?

I found this project is based on an open source project on github: https://github.com/Commodore-Bench/DELA-EPROMMER-II https://github.com/RetroNynjah/DELA-EPROMMER-II-27512-extension Searching on the web I also found a more extensive german manual that I translated to english with Google. I also translated with an hex editor the C=64 software from german to english; I searched for every german sentence and I translated with Google too, adapting the english sentences into the n. of chars of the german sentence. I didn't try it yet because I'm waiting for the component to arrive here from Aliexpress.

I will tell you more info as soon as I can test it a bit...

Some updates.... I assembled and used the programmer and I can say that it works fine (I didn't test it with the 512k eprom expansion, though). You can copy an EPROM on the fly and/or store the content on floppy disk. However I don't know exactly how to convert a BIN file to a PRG file. The programmer can make a copy of an eprom, and/or save the dump on disk and use it for further programming (I tested it). I looked at the content of the saved dump (it's saved as a PRG file on disk) and I discovered it's saved in blocks that don't follow the sequence you expected. The blocks are mixed. The DELA programmer software of course knows how to handle the PRG, because if you recall a dump from disk and program an eprom, the result will be perfectly identical to the source EPROM. So, it's good if you want to dump an EPROM content and use it for programming an EPROM later, or if you want to copy an EPROM on the fly. It's quite funny and vintage, but if you need an eprom programmer and don't own one yet, forget it and buy a modern eprom programmer, it will be way more useful and probably cheaper. About the german software, I translated it in "english-ish" (using Google, an hex editor and some imagination)... I only need to find an easy way to release it...

I wish to add some info about the difference between the eprom dump from a 2764 eprom (PRG) and an 8Kb file you can get from the web (BIN). -- The two first bytes of the PRG should be the load address (00 10 = $1000). -- The first byte of the BIN file is the last byte ($2000) on the PRG file; if you take the PRG and trim the first two bytes, and then cut the byte at the $2000 address, and add it on the head of the PRG file (at $0000), you will get a comparable code with two big differences: --- the blocks $0000 – $07FF and $1000 – $17F0 are the same in PRG and BIN --- the block at $0800 – $0FFF in the PRG is written at $1800 – $1FFF in the BIN -- the block at $0800 – $0FFF in the **BIN** is written at $1800 – $1FFF in the **PRG** I don't know why DELA eprommer swap the addresses $0800-$0FFF and $1800-$1FFF when it saves on disk and vice versa when read from disk.

Does anybody know if is there any software that can take a BIN file and convert it to PRG ?

Helo, I do not know how did you measured the VPP voltages, I tried many different 12-21-25 volt eproms and they all programmed well, without any problem. These voltage values may be be in wave puls form and may not me measured with simple voltmeter. If eprommer is not programming 21 or 25 volts VPP eproms please check all components and solders, And please check your commodore64 power suply 9V AC and 5V DC voltages (while C64 is working). If you try and can not program 21V and 25V VPP eproms then please send me detailed photos of Dela Eprom Programmer from both sides to: c64istanbul@bikom.com

9V Ac and 5V is ok. With the Test Menu i measured Pin 1 of the Zif Socket for every Voltage. I will prepare fotos and sent it immediadly. Thanks. for your offer

Did you try to program 21V and 25V VPP value eproms? Measured voltage values do not reflect the real voltages, because of the puls form vawes, while programming.

I tried 256 eproms of different brand with 21V, break after a view bytes. the fotos are sent.

I replied your e-mail. Thank you.

I used, BC237 B and BC558 B.

Thanks a lot for the hint!

You're welcome.:)

Thank you Eddie van Loon.:) I used eprommer ii for many years.

Thank you. :)