Recent content by modem7

I have released a new version of Ruud's Diagnostic ROM. It is now at version 4.8 Available at minuszerodegrees.net Bug fix #1 Version 4.0 introduced the following problem. If the IBM made MDA card ('IBM Monochrome Display and Printer Adapter') is used: • No output to screen. • No...

Thank you. I updated the Acculogic sIDE-1 entry at [here]. ( A page refresh in your browser may be required. )

Power is good, and we have a good idea of what equipment you have to aid diagnosis. I forgot that you had mentioned the POST card earlier. Maybe it is the 'Example of a modern POST card' one shown at [here]. IRDY appears to be related to a signal on the PCI bus, not the ISA bus. I see that you...

There is one way that will definitely work, assuming fully functional hardware: Step 1: Get yourself a DOS boot floppy/diskette. Perhaps create a thread in the 'wanted' section of these forums. On that boot floppy/diskette, have the FDISK.COM and FORMAT.COM programs. Step 2: Wipe the 8MB CF...

Which hints to me your level of soldering skill. An incorrect failure address of 5040 being reported by the SLDR is known of. Excellent. Considerations: - Faulty RAM chips. - Partially faulty U12 (see diagram at [here]). - Bad soldering / damaged PCB,

To my astonishment, I experienced what you do. SLDR with IBM MDA = Works RDR with IBM MDA = Something wrong during checkpoint 0 <----------- Why ??? Using a third party MDA card instead: SLDR with third party MDA = Works RDR with third party MDA = Works <----------- So what is special about...

My soldering technique varies according to the job, but for dual-in-line IC's, I use the technique shown at [here].

Thank you. I added that 'KW-530 Series' manual to the Kouwei section of [here]. ( A page refresh in your browser may be required. )

I brought out a 5150 motherboard of type 16KB-64KB. I plugged in an IBM MDA card, and PSU. I attached a speaker. I put in the SLDR. Nothing extra. I removed a RAM chip from bank 0, in order to verify speaker operation. At power-on, SLDR screen output appeared, but no speaker beeps. Later...

Some kind of 5150 motherboard problem is also a possibility. I trust you. Back at post #9, in regard to the use of the SLDR, you wrote, "If I plug in the MDA card, it immediately fails on the first test, 1 Hi/Lo and actually a long beep I would call it." I normally do not have a speaker...

Both SLDR and RDR display characters on screen by writing bytes directly to video RAM. For example, on an MDA card, to put a '3' in the top-left corner, the ASCII byte for '3' is written to address B0000, and the attribute byte of 7 is written to the following address.

I have seen that behaviour myself. With no U28 in place, when a read of a motherboard address corresponding to U28 is done, there is nothing driving a voltage onto the external address bus. The byte read can vary from motherboard to motherboard. More on the situation follows (comments that I...

These are resistor networks ('RN'). Only sometimes are resistor networks used in a termination role. Looking at the circuit diagram of the type 1 motherboard, RN1 through RN3 are not used as terminators. Good. Yes. +5.34V will be interpreted as a TTL high level. A multimeter is unsuitable for...

If the fan in the PSU is AC powered, rather than DC, then the fan is still going to turn. Is the +5V present ? I agree. And if the poor socket-pin-to-solder-pad alignment is not the problem cause, it may be a problem down the track.

I have two of the following CD caddy, but I do not know what CD drives that they work in. CD caddy - 1.jpg CD caddy - 2.jpg CD caddy - 3.jpg CD caddy - 4.jpg CD caddy - 5.jpg