HD pinout confusion - Page 1
Forum section: electronics / beginners

author: algorithm
author_rank: Regular Contributor
timestamp: January 30, 2017, 04:43:19 pm
content: Trying to connect a 50 pin IDC to a 40 pin IDE.Am I missing something or do some signals not translate directly?I know databus would go to data, but Im confused about I/O, as well as BSY, MSG, REQ, SEL, RST, ATN, and C/D. also confused about the +/- pins.Would I/O on the SCSI side go to IORDY, DIOR, or IOCS16?Hopefully someone is familiar with these differences, I know this forum is full of brilliant minds so I figure this is the best place to ask.Thank youand I apologize for my lack of understanding. (in case this is a really stupid question)(also I think I could get away with using single ended SCSI, instead of the differential pinout provided. but better safe than sorry.)50 pinPin Name Dir Description01 GND --- Ground02 GND --- Ground03 +DB0 <-> +Data Bus 004 -DB0 <-> -Data Bus 005 +DB1 <-> +Data Bus 106 -DB1 <-> -Data Bus 107 +DB2 <-> +Data Bus 208 -DB2 <-> -Data Bus 209 +DB3 <-> +Data Bus 310 -DB3 <-> -Data Bus 311 +DB4 <-> +Data Bus 412 -DB4 <-> -Data Bus 413 +DB5 <-> +Data Bus 514 -DB5 <-> -Data Bus 515 +DB6 <-> +Data Bus 616 -DB6 <-> -Data Bus 617 +DB7 <-> +Data Bus 718 -DB7 <-> -Data Bus 719 +DBP <-> +Data Bus Parity (odd Parity)20 -DBP <-> -Data Bus Parity (odd Parity)21 DIFFSENS ?22 GND --- Ground23 res - Reserved24 res - Reserved25 TERMPWR <-> Termination Power26 TERMPWR <-> Termination Power27 res - Reserved28 res - Reserved29 +ATN <-- +Attention30 -ATN <-- -Attention31 GND --- Ground32 GND --- Ground33 +BSY <-> +Bus is busy34 -BSY <-> -Bus is busy35 +ACK <-- +Acknowledge36 -ACK <-- -Acknowledge37 +RST <-> +Reset38 -RST <-> -Reset39 +MSG --> +Message40 -MSG --> -Message41 +SEL <-> +Select42 -SEL <-> -Select43 +C/D --> +Control or Data44 -C/D --> -Control or Data45 +REQ --> +Request46 -REQ --> -Request47 +I/O --> +In/Out48 -I/O --> -In/Out49 GND --- Ground50 GND --- Ground40 pinPin Name Dir Description1 /RESET --> Reset2 GND --- Ground3 DD7 <-> Data 74 DD8 <-> Data 85 DD6 <-> Data 66 DD9 <-> Data 97 DD5 <-> Data 58 DD10 <-> Data 109 DD4 <-> Data 410 DD11 <-> Data 1111 DD3 <-> Data 312 DD12 <-> Data 1213 DD2 <-> Data 214 DD13 <-> Data 1315 DD1 <-> Data 116 DD14 <-> Data 1417 DD0 <-> Data 018 DD15 <-> Data 1519 GND --- Ground20 KEY - Key (Pin missing)21 DMARQ ? DMA Request22 GND --- Ground23 /DIOW --> Write Strobe24 GND --- Ground25 /DIOR --> Read Strobe26 GND --- Ground27 IORDY <-- I/O Ready28 SPSYNC:CSEL ? Spindle Sync or Cable Select29 /DMACK ? DMA Acknowledge30 GND --- Ground31 INTRQ <-- Interrupt Request32 /IOCS16 ? IO ChipSelect 1633 DA1 --> Address 134 PDIAG ? Passed Diagnostics. Used for 80-pin cable detect.35 DA0 --> Address 036 DA2 --> Address 237 /IDE_CS0 --> (1F0-1F7)38 /IDE_CS1 --> (3F6-3F7)39 /ACTIVE --> Led driver40 GND --- Groundthank you again

author: Cliff Matthews
author_rank: Unknown
timestamp: January 30, 2017, 06:15:19 pm
content: Forget about matching just signal names, there are much grander problems... IDE (ATA, serialized or not) uses an older Seagate ST506 (412?) command format and the terminations are single-ended. SCSI uses another data-rate and command structure and signals are typically paired differential. This is so much about apples and oranges, that this may be the only response you get.. sorry!

author: tooki
author_rank: Super Contributor
timestamp: January 31, 2017, 12:36:09 am
content: Indeed, IDE and SCSI are wildly incompatible on multiple levels.I suspect this might be an XY Problem. Can you tell us what problem you want to solve, since your proposed solution cannot and will not work?(IDE to SCSI adapters for hard disks have existed in the past, for putting IDE disks in old workstations and Maca that only have SCSI. But they had the reputation for being finicky and unreliable.)

author: algorithm
author_rank: Regular Contributor
timestamp: January 31, 2017, 12:49:19 am
content: well I have this old piece of hardware that works a lot like a SCSI adapter, except it uses 50 pin IDC internally. it originally had a mechanical drive in it, but the drive is beyond repair, so now I want to replace it with something, I have a 40 pin IDE CF card adapter that I would rather use in its place. so the 40 pin IDE is on a CF adapter, but I worried this would be the case. no need to apologizeI appreciate the answers.Im just trying to put something in its place so its not trash.

author: james_s
author_rank: Super Contributor
timestamp: January 31, 2017, 01:26:49 am
content: Ok I'm confused here. IDE is Integrated Drive Electronics, aka the ATA interface, it originated as a hard drive with an integrated controller, the cable being a buffered extension of the 16 bit ISA bus itself uses a 40 pin connector.IDC = Insulation Displacement Connector, these are typically used on ribbon cables to connect hard drives and such but have no relation to the actual interface standard.SCSI = Small Computer Systems Interface, this appeared in the mid 80s evolving from the older SASI interface as a high performance bus for internal and external peripherals. It originally used a 50 pin connector and later evolved into faster standards that are more or less backward compatible.In a nutshell, you absolutely cannot simply adapt one of these to another, they are completely different and even if you did electrically connect them they still wouldn't know how to talk. It's like trying to plug a PCI card into a NuBus slot, it just won't work. You do have a couple of options though, there are products like the SCSI2SD which emulate a SCSI hard drive and use a micro SD card for storage. Another option is to pick up a SCA hard drive and an adapter to go from SCA to 50 pin. These drives were commonly used in servers for quite a few years so they are still easily available. My favorite are the Seagate Savvio 2.5" drives because they're very quiet and consume less power than the 3.5" type which are mostly high speed 10k-15k RPM, they whine like a dentist drill.

author: tooki
author_rank: Super Contributor
timestamp: February 03, 2017, 02:19:28 am
content: Quote from: algorithm on January 31, 2017, 12:49:19 amCan you just name and document the thing, instead of giving us your vague description? Name, model number, manual, pictures... something concrete.