The first thing to know is that before this solution, most data was stored on punch cards. They encountered many problems, the main ones being that they took up a lot of space and it was difficult to find the information they were looking for. Additionally, they were made of quite delicate material and could break quite easily, rendering them unusable.
Curiosities and myths about the IBM 305 RAMAC
It’s always interesting to look back in time to see how technology has evolved and progressed. One of those that has evolved the most is storage, capable of carrying a huge amount of information in one’s pocket, but there was a time when this was not the case.
The first storage solution was the IBM 305 RAMAC. Say that acronym RAMAC they mean RAM accounting system, which in Spanish is an accounting system with RAM. This system measures 1.52 meters long, 1.73 meters high and 74 centimeters deep.
The first unit was marketed in September 1956. Interestingly enough, one could buy one of these units or rent it for a monthly fee. More precisely, the unit It cost around $34,500., around 300,000 dollars today, counting inflation. It could to rent outFor about $3,200, which would currently be around 29,000 dollars per month.
Although this may seem expensive, it represents a great saving of time, space and resources for the institutions that use it. He offered a storage equivalent to 64,000 punch cards, which meant huge savings. You could access information much more easily and at a lower cost.
But what do we usually talk about? IBM 305 RAMAC like a hard drive, reality it’s a commercial computer. It consisted of a card punch, central processing unit, power supply, operator console/card reader, and printer.
Additionally, the 305 RAMAC was one of the latest vacuum tube computers manufactured and built by IBM.
Weight, the greatest of its myths
You’ve probably seen a photograph of the unit being flown or unloaded from a truck by multiple operators. These images are real and it was a huge, complex and very heavy system.
It is normally stated that the IBM 305 RAMAC weighed over a ton and this is not entirely true. The system itself had a I really weigh 907 kilos, which is already a lot. So why is everyone saying this system weighs over a ton?
Well, the problem lies in the hard drive itself, which required an additional air compressor. This compressor was independent and weighed around 200 kilos, so it is said that this system weighed more than a ton. This is not entirely false, but it is inaccurate.
His ability, another mistake
The storage unit consisted of 50 disks measuring 61 centimeters in diameter that rotated at 1,200 rpm. This is all correct, there are no errors in this information, although there are capacity discrepancies. Normally this indicates a capacity between 4.4 MB and 5 MBbut these often claimed capabilities are Incorrect.
We know that the disk could store 5 million characters. The system used an 8-bit registration code, of which 6 bits represented the data, in addition to having a parity bit and a space bit. The capacity being expressed in data bits, it is necessary to carry out a simple operation which consists of multiplying the characters which could be stored by the division between the data bits and the recording bits. It looks like this: 5 million characters * (6/8) = 3.75 MB
Therefore, the useful capacity store the device is 3.75 MB. Now that we have the formatted (useful) capacity, we need to know the raw capacity, which is the total capacity of the disk.
The capacity of 4.4 MB would be given because the calculation is carried out with 7 bits out of the 8 recorded. For this hypothesis, the 6 data bits plus the parity bit are taken into account.
