retro:salvage-content-from-360k-floppy-disks
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retro:salvage-content-from-360k-floppy-disks [2020/01/23 09:31] Ilias Iliopoulos [Step 4. File transfer] virus warning addition |
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| - | ====== Salvage content from 5 1/4" 360K floppy disks ====== | + | ====== A Guide to Salvage content from 5 1/4" 360K floppy disks ====== |
| ===== Introduction ===== | ===== Introduction ===== | ||
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| The article is a bit lengthy, but it is like archaeology: You need to have a rich background in order to analyse a pottery fragment... | The article is a bit lengthy, but it is like archaeology: You need to have a rich background in order to analyse a pottery fragment... | ||
| - | I am sorry for the terrible pictures. Time was pressing to finish as soon as possible and free the space occupied by those components, so documenting was not a priority. Family guys shall understand. | + | I am sorry for the terrible pictures. Time was pressing to finish as soon as possible and free the precious room space, so documenting was not a priority. Family guys shall understand. |
| ===== Preface ===== | ===== Preface ===== | ||
| - | The year is currently 2020. While working on a project, I remembered that I have implemented a similar algorithm some time in the previous century, back in 1987. The code was part of my personally designed and implemented 6502 development system, which included a micro-controller card equipped with an 6502 microprocessor, along with several peripherals. I used to develop in Assembly on an IBM-PC compatible computer, a **Lingo PC-88 XT** with an 8088 processor, 640K of RAM, two 5 1/4" 360K floppy disk drives, no hard disk and a CRT composite monochrome monitor, which I have purchased second-handed from a friend, at a price of 200.000 GRD, sometime around 1983. I have expanded the system with some custom-made expansion boards of my design and later I was happy to add a mouse which occupied the serial port. | + | The year is currently 2020. While working on a project, I remembered that I have implemented a similar algorithm some time in the previous century, back in 1987. The code was part of my personally designed and implemented 6502 development system, which included a micro-controller card equipped with an 6502 microprocessor, along with several peripherals. I used to develop code in Assembly on an IBM-PC compatible computer, a **Lingo PC-88 XT** with an 8088 processor, 640K of RAM, two 5 1/4" 360K floppy disk drives, no hard disk and a CRT composite monochrome monitor, which I have purchased second-handed from a friend, at a price of 200.000 GRD, sometime around 1983. I have expanded the system with some custom-made expansion boards of my design and later I was happy to add a mouse which occupied the serial port. |
| - | Several other computers have found their position on my desk over the years and the Lingo was exiled in the attic, accompanied by several old laptops. Not all laptops - I still have an IBM 2645 Thinkpad which used to run Windows 95 in my lab. But its purpose now, in its beautiful leather-like bag with the IBM logo on it, is to be a door stopper!!!! None of those computers had support for 360K drives. In the evolution process, it was the first to become obsolete. | + | Several other computers have found their position on my desk over the years and the Lingo was exiled in the attic, accompanied by several old laptops. Not all laptops - I still have an IBM 2645 Thinkpad which used to run Windows 95 in my lab. But its purpose now, in its beautiful leather-like bag with the IBM logo on it, is to be a door stopper!!!! I still have a Compaq Armada laptop, which I used to run the **Sniffer Network Anallyzer** which I had purchased at the enormous price of 2.000.000 GRD. Wireshark is now free!!! None of those computers had support for 360K drives. In the evolution process of computers, the floppy drive was one of the first components to become obsolete. |
| Fortunately, I have kept my stock of 360K floppy disks safely in a drawer, away from humidity and temperature extremes. It was not long before I located the floppy that I wanted. | Fortunately, I have kept my stock of 360K floppy disks safely in a drawer, away from humidity and temperature extremes. It was not long before I located the floppy that I wanted. | ||
| - | I had to sustain a lot of laughs from my similar aged friends when I asked them if they happened to have a disk drive that could read 360K Double-Sided Double-Density floppy disks and transfer the files to a USB stick or over the network! | + | I had to sustain a lot of laughs from my same-aged friends when I asked them if they happened to have a disk drive that could read 360K Double-Sided Double-Density floppy disks and transfer the files to a USB stick or over the network! |
| After realizing that I had been left on my own, I started to explore some not so obvious options. The most promising was to exploit another 386 PC which is in the pre-exile attic phase and has an IDE bus, one 3" 1.44M floppy drive and several hard disks. It used to run Windows 2000, as well as a version of SuSe Linux and is still operational. The plan was to extract the 360K disk drive from the Lingo, connect it to the IDE bus of the 386, read my floppy and transfer its contents to a small capacity USB stick. At least, USB was supported by the motherboard of this 386 after its last and final BIOS upgrade. Unfortunately, in spite of the fact that the BIOS was set-up to recognize 360K drives, both Windows 2000 and SuSe Linux 7.1 were not equipped with the proper drivers, resulting in total failure. Really disappointed by Linux! | After realizing that I had been left on my own, I started to explore some not so obvious options. The most promising was to exploit another 386 PC which is in the pre-exile attic phase and has an IDE bus, one 3" 1.44M floppy drive and several hard disks. It used to run Windows 2000, as well as a version of SuSe Linux and is still operational. The plan was to extract the 360K disk drive from the Lingo, connect it to the IDE bus of the 386, read my floppy and transfer its contents to a small capacity USB stick. At least, USB was supported by the motherboard of this 386 after its last and final BIOS upgrade. Unfortunately, in spite of the fact that the BIOS was set-up to recognize 360K drives, both Windows 2000 and SuSe Linux 7.1 were not equipped with the proper drivers, resulting in total failure. Really disappointed by Linux! | ||
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| You can also construct null modems with a 9-pin connector on one side and 25-pin on the other, but this discussion has already gone far enough. | You can also construct null modems with a 9-pin connector on one side and 25-pin on the other, but this discussion has already gone far enough. | ||
| - | One must be extremely careful in handling the RS-232 pins and wires. RS-232 electrical characteristics require one logic level (a **"space"** or **logic LOW**) to be in the range between **+3V** and **+15** Volts and the other logic level (a "mark" or logic HIGH) in the range between **-3V** and **-15V**. Voltages between **-3V** and **+3V** are not allowed. The confusion with voltages and levels increases because when the line is idle, its level is HIGH, which is negative voltage and when the transmitter starts sending, it sends a start bit which is logic LOW and which is positive voltage. Control signals, when raised, become LOW which is a "space" with a positive voltage. Anyway, we do not need to go into details, just remember that we **MUST AVOID CONNECTING BY MISTAKE TX WITH THE TX OF THE OTHER SIDE**, especially when one is transmitting. Old components usually were not protected from such short-circuts, and a connection error may result in frying the serial driver chip. | + | One must be extremely careful in handling the RS-232 pins and wires. RS-232 electrical characteristics require one logic level (a **"space"** or **logic LOW**) to be in the range between **+3V** and **+15** Volts and the other logic level (a "mark" or logic HIGH) in the range between **-3V** and **-15V**. Voltages between **-3V** and **+3V** are not allowed. The confusion with voltages and levels increases because when the line is idle, its level is HIGH, which is negative voltage and when the transmitter starts sending, it sends a start bit which is logic LOW and which is positive voltage. Control signals, when raised, become LOW which is a "space" with a positive voltage. Anyway, we do not need to go into details, just remember that we **MUST AVOID CONNECTING BY MISTAKE TX WITH THE TX OF THE OTHER SIDE**, especially when one is transmitting. Old components usually were not protected from such short-circuts, and a wiring error may result in frying the serial driver chip. |
| I use a device which identifies the active pins with LEDs, so after connecting to each side separately, I am certain that I do not provoke a short-circuit. It is better to remove this device after the test, because the energy consumed by the LEDs may cause problems, in case the line drivers cannot provide so much current to light the LEDs. | I use a device which identifies the active pins with LEDs, so after connecting to each side separately, I am certain that I do not provoke a short-circuit. It is better to remove this device after the test, because the energy consumed by the LEDs may cause problems, in case the line drivers cannot provide so much current to light the LEDs. | ||
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| Good luck! | Good luck! | ||
| + | ~~DISQUS~~ | ||
retro/salvage-content-from-360k-floppy-disks.1579764718.txt.gz ยท Last modified: 2020/01/23 09:31 by Ilias Iliopoulos