42 pin eprom programmer drivers#
42 pin eprom programmer software#

This is particularly important when programming CMOS parts, otherwise the timings specified in Intel datasheets cannot be achieved, instead arbitrary delays would have to be inserted throughout the programming algorithm to allow charge to bleed away from these inputs, as is frequently seen in other efforts.

42 pin eprom programmer drivers#

Warning to those building other designsДЄll home-brew MCS-48 programmers have pin drivers resembling the above, mine differs in that it uses a P-Ch FET to get the fastest possible rise time, and a 2K2 вЂњpull-downвЂќ is also present to keep fall times within specification (< 2ОјS). There is a little bit of backstory about it here.Д«uild resources are linked to at the end of the page. 8755AДЄn adapter is required to program the 8755A. Note that not all MCS-48 mask ROM parts will allow the code to be read out. Vpp = 25V for 8741.ДЄs with above, NEC parts also supported. This programmer supports both NEC and Intel parts. These were made also made under license by NEC. Supported devices Regular UV erasable MCS-48

42 pin eprom programmer software#

This programmer can generate all of them and software select between them as needed. Programming and reading the list of devices mentioned in the title requires quite a range of different voltages including 5V, 12V, 18V, 21V, 23V and 25V. This is not so much the case for MCS-48 as hardware can be obtained for a hundred dollars or so, however, I wasnвЂ™t going to pass up on the opportunity to build another one of these, and, mine can be built for less money plus it has the ability to read mask ROMs.ДЄt the same time as I designed the shield, I also built an entirely new project based on one of these. In the past I have built a series of Arduino shields for programming old UV erasable devices for which programming hardware is difficult to come by ( read more here). With the exception of some newer dated parts, usually 8042 / 8049, if youвЂ™ve got the thing, you can steal the code from it, disassemble it, and learn lots about the equipment itвЂ™s fitted to.

The nice thing about the MCS-48 is that it largely predates the concept of code security. Recently I was repairing an old piece of equipment which was based on IntelвЂ™s first microcontroller: The MCS-48.