#2716 eprom programmer software#
#2716 eprom programmer code#

The alternative is to physically cut the A11 line in the emulation lead - very much a last resort.

This will eliminate any possibility of over dissipation within S4. After the programming cycle is complete, the LOAD.

#2716 eprom programmer code#

We recommend that you copy the code from addresses 00000-007FF to address 00800 (use the MOVE command) and emulate as a 2732. Frogramming time for a 2716 EPROM is approximately 105 seconds. Although we drive this line low internally during emulation, it is possible for the target system to override the pull down, which results in the target seeing the code at address 00800 rather than 00000. When emulating 2716s, many target systems have pin 21 linked to Vcc. We recommend the first solution where possible. The cathode (striped end) should be to pin 21, the anode to pin 24, and this again will hold pin 21 high. The other, when the code MUST be programmed from address 00000, is to clip a silicon diode (eg 1N914) into the ZIF socket with the device.

One is to load the code to be programmed at address XX800 rather than address XX000, or move it there after loading, and program the device from this address this will ensure that A11 is always held high during read operations. With this task done, it was time to fill one of these with 2k of correct binary code. For some reason the first byte was always bad After the UV eraser arrived I could blank the 2716 EPROMS I had available. However, we cannot reconfigure A11 as a control line with S4's hardware, and as a result, 2716s will not load or verify properly in any address range where A11 is low, although they will program correctly from any address. Prior to getting the eraser, I had two blank 27C16 chips which I had tried to program without success. Note that the addresses of the 2716 range from 0x0000 - 0x07ff. For example a 2716 is nominally 16k (2K 8-bit words) and a 27128 is 128k (16k 8-bit words).

#2716 eprom programmer software#

Software control of 2708/2716 programming ection-no. Most 2716s require this pin to be held high to read. Subsequent digits indicate the number of kbits of memory in the device. Programming sockets are DIP switch addressable to any 4K boundary. The 2716 takes Vpp on pin 21, which on S4 is address line A11.