Re: Chinon Fz-502 5.25" floppy drive

Posted on 2020-05-09, 16:36

by

by Bellator

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Cannot do that. I am confused right now because I am not sure if you have not read all my posts or you have not undestood them. I have done what I say that I have done in this thread, and not another thing. So, definitely, I can do it. 1.22MB drive; you can only write and read only to 1.22MB disks. …

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Re: Chinon Fz-502 5.25" floppy drive

Posted on 2020-05-09, 10:26

by

by Bellator

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have been wondering how HD drives face the problem of having to deal with both types of disks, so I have searched for the schematic of the Chinon FZ-506: Chinon FZ-506 Schematic Diagram.jpeg For DD disks it uses a 3.3 Kohm resistor (R50) and for HD disks it seems that a switch is turned on to …

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Re: Chinon Fz-502 5.25" floppy drive

Posted on 2020-05-08, 05:50

by

by Bellator

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

By the way, I had not realized until now but there are more differences between both circuit boards. JP4, JP5 and JP8 differ from each other and in the first board there are green marks over the JP5 and JP8 places. I wonder why.

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Re: Chinon Fz-502 5.25" floppy drive

Posted on 2020-05-07, 21:51

by

by Bellator

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

FIXED UP! Now it can read, write and format Double Density disks perfectly. It can also read High Density disks but, as a result of the fix, it cannot write or format them. I am going to relate the repair process. May it help people repair their drives. First I searched the Internet for the circuit …

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Re: PCChips m919 cache stick not working

Posted on 2020-05-02, 16:37

by

by Bellator

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

There were 2 types of cache modules, 3.3V or 5V. Source? First time I ever heard of this. I own the M919 as well and played around with many CPUs. 4V Cyrix, 3.3V AMD, and finally 5V POD. Always with the same cache module. The manual doesn't mention different modules either. And it doesn't make …

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Re: PCChips m919 cache stick not working

Posted on 2020-05-02, 16:20

by

by Bellator

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

What voltage is your processor? There were 2 types of cache modules, 3.3V or 5V. The voltage was set with the same jumpers as for the processor. It seems that your module is for 3.3V.

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Re: Some EDO results for ALI M1487/89

Posted on 2020-02-08, 18:30

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by Bellator

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have run some benchmarks to compare EDO performance against FPM. EXP8449 motherboard (ALi M1487/M1489) with Terminator 486/5x86 system PCI-25 MAY/13/1996 BIOS AMD 5x86 @ 160 MHz (4x40 MHz) 256 KB cache @ 2-1-1-1 S3 Virge 325 2MB Filename dos.jpg File size 94.05 KiB Views 566 views File comment MS …

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Some EDO results for ALI M1487/89

Posted on 2020-02-02, 19:28

by

by Bellator

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have tried in my EXP8449 (ALI M1487/89) board several BIOSes of other boards and I have found that they work with different timmings for the different BIOS settings when using EDO RAM. One board with Fast/Fast settings may be faster than other with Fastest/Fastest settings just because of how the …

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Re: Can you help me identify theese boards?

Posted on 2020-01-20, 17:53

by

by Bellator

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

i have a hp pavilion s370 board that came with one of those modem/sound daughter board setups. perhaps this came from one of those? this is not something id expect to see in a typical tower. the short mid towers used this because they were so cramped. Yes, all this seems to come from a HP Pavilion …

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Re: Can you help me identify theese boards?

Posted on 2020-01-19, 20:42

by

by Bellator

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Looks like a socket A mainboard to me. Socket A with black ATX panel? Never. ATX and SDRAM only but without AGP slot. S7 or SS7? From the looks of it, it's a SIS based Socket 7 board. Most likely SIS530, because there's a bulky southbridge. EDIT: That's ASUS P5-99VM . EDIT2: The PCI card is one of …

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Can you help me identify theese boards?

Posted on 2020-01-19, 18:51

by

by Bellator

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

It's a priceless ad and the seller doesn't know what he is selling. He won't send me any photo unless I tell him before how much I'm willing to pay. I've failed to identify both boards. It's a strange motherboard, ATX and SDRAM only but without AGP slot. S7 or SS7? The other one looks like a PCI …

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Re: EXP8449's battery

Posted on 2020-01-11, 01:29

by

by Bellator

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I already found it. The voltage of the battery was so low because it was feeding the entire motherboard when the computer was off. The D1 diode died shorted. When the computer is on, D3 diode is open and the 3,55 volts that I was measuring is the normal voltage of the battery. J1 connector: 1-2 …

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EXP8449's battery

Posted on 2020-01-09, 13:27

by

by Bellator

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

My EXP8449's battery has just died. It's a 1/2AA Tadiran TL-5151 non-rechargeable lithium battery. I think that the direct replacements are Tadiran TL-4902 or SL-850. It has lasted 200,000 hours, I don't complain, but there's maybe something strange here. I have been watching the voltage of the …

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Re: Chinese 10ns SRAM for L2 cache

Posted on 2019-07-20, 19:50

by

by Bellator

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I bought ten ISSI IS61C1024-10N chips in aliexpress. One was dead, the other nine worked (one of the nine would prevent the computer to boot if it was placed in the first socket, but it worked in the other three sockets). My bet is that they are not original ISSI chips, and that they are not 10 ns …

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Re: Chinon Fz-502 5.25" floppy drive

Posted on 2019-07-20, 19:22

by

by Bellator

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have found that the drive works well with high density disks but it does not with double density disks. I have tried 4 different 96 tpi MD2-HD disks and I can read, write and format (360 KB of course, because it is a 360 KB drive) all of them without an error. All the 48 tpi double density disks ( …

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Re: Any interesting graphic card in this photo?

Posted on 2019-03-24, 08:22

by

by Bellator

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have identified several of them: Aopen Geforce 2 MX400: 1st row, 4th card Dell ATI Rage 128 Pro Ultra: 1st row, last card; 3rd row, last card S3 Savage 3D: 2nd row, 5th card Geforce 4 MX440: 2nd row, 6th card ATI Radeon 9250: 3rd row, 1st card S3 Trio64: 3rd row, 2nd card 1st row, 1st card maybe …

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Any interesting graphic card in this photo?

Posted on 2019-03-23, 10:53

by

by Bellator

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

What about the second starting on the right of the last row? Filename graphic_cards.jpg File size 59.47 KiB Views 449 views

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Re: ALI1487 / 1489 dma support win95 + dos udma enabler

Posted on 2019-01-15, 00:02

by

by Bellator

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

From these results, the standard driver appears faster at sequential read/writes. But from your previous benchmarks though, the ALi driver was faster at writes and slower at reads. Are you able to setup a RAM drive and re-run the timed tests with the hard drive writing to the RAM drive and the RAM …

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Re: ALI1487 / 1489 dma support win95 + dos udma enabler

Posted on 2019-01-13, 23:14

by

by Bellator

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have timed file transfers between both hard disks using a 123MB file. I have defragged the hard disks first, and I have only taken one time per session restarting the computer after each test. With aliide driver: - From Maxtor Partition 1 To Maxtor Partition 2 (primary master): 123 s - From Maxtor …

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Re: PATA 133, SATA 150 or SCSI U160 for 486 PC

Posted on 2019-01-12, 12:29

by

by Bellator

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Maybe what you're looking for is a Pentium? ;-) I don't have to look for a Pentium because I already have one (IBM PC 350). ;-) In all seriousness, what performance issues are you specifically trying to cure? The only time I've noticed disk I/O to be a bottleneck in DOS is during installs or …

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