EZoFlash форум

Hello,

I recently purchased a Sivava Willem PCB50B, to back up some old EPROMs from a rackmount synthesizer I own.

The EPROM is a 27C256 which has the operating system for my synthesizer loaded on it. I am using a 12v 1a adapter, I have set the DIP switches and jumpers as per the software instruction for a 27C256, I have positioned the device in the socket as per the software.

When I try to read the EPROM the software completes the read process, but the buffer is full of "FF". Also, if I run a "blank test" the software reports that the device is empty!
This quite clearly is not true, because if I put the EPROM back in my synthesizer it boots up fine.

I have tried different versions of software - 98D12c3, 0.98c, 0.97ja - but all of them act the same way.

I have run through the Test H/W by turning the pins on and off:-

vpp = 12.57
vcc = 4.99
A9 = 2.89
All the rest read 4.33(excluding GND)

I don't have much experience with this kind of thing, do these readings look correct?

SW 0.98d12c3 - apply jumpers in pcb45(pcb50) mode
SW 0.97ja - apply jumpers in pcb35 mode.
Recheck all settings according guide in software
was chip placed correctly , chip pin1 to ZIF32/3
-------------
Go Test H/W and set dipswitches according picture.
Go Devices and select chip 29F010
Read (without target chip !)
Check buffer and find content 0x04, 0x06.... Is it ?
What LPT mode selected in your PC BIOS ? Change from ECP or ECP/EPP to Normal.