Brand new IBM 5155 Model F XT
Posted: 23 Mar 2019, 13:27
Hi guys, thought I'd share my experience with this lovely, industrial-looking Model F which doesn't get that much attention from the community. I bought it for £220 shipped, which isn't bad for a brand new Model F. Unfortunately, I don't think this keyboard ever came with an original box like the PC versions. I cannot upload images at all, or create an account on imgur, so this video will have to do:
https://www.youtube.com/watch?v=WKL2sqVXAM0
How does this keyboard compare to a regular Model F XT? Well, as it came with a "laptop", they obviously wanted to make it lighter. The case is a thick plastic shell, just like the top case of an XT- except this one doesn't have a back panel that can be opened. Instead, there is a Model M-like injection-moulded plastic insert forming the top of the case, which can be unclipped from the main case. This is a relatively flimsy system, as the tabs may snap if you're not careful - and hairline cracks appear in the plastic next to the tabs. For this reason, I'll be showing the internals of my other IBM 5155 keyboard which has already been opened.
Inside, the chassis is screwed into the main case. IBM used aluminium instead of steel to keep the weight down, which is pretty clever really, as it doesn't feel any less rigid.
It does have an impact on the sound, however. The thock is a shallower "thwack" sound compared to the more dense sound the XT's steel assembly has. The pitch of the click is definitely lower on my IBM 5155 keyboards compared to other Models F I've heard. Compared to the other 5155 keyboard, the NOS one is clickier and the thock isn't as pronounced. I don't think the spacebar sounds as good though. Most of the keys also don't ping much, whereas a few keys on the right of the main block do have a noticeable ping. I really like ping, and I find it interesting how it varies so much between models. Why do they all have a different pitch between models? Why are some pingier than others? Is it the springs drying out with use? Is it minor changes in tension? I had a UK Model F XT from 1985 with an extremely pingy spacebar. After a foam replacement and even using the same spring/flipper, the spacebar ping was gone. I also completely ruined the key feel, but that's a story for another time!
Anyway, what do you guys think?
https://www.youtube.com/watch?v=WKL2sqVXAM0
How does this keyboard compare to a regular Model F XT? Well, as it came with a "laptop", they obviously wanted to make it lighter. The case is a thick plastic shell, just like the top case of an XT- except this one doesn't have a back panel that can be opened. Instead, there is a Model M-like injection-moulded plastic insert forming the top of the case, which can be unclipped from the main case. This is a relatively flimsy system, as the tabs may snap if you're not careful - and hairline cracks appear in the plastic next to the tabs. For this reason, I'll be showing the internals of my other IBM 5155 keyboard which has already been opened.
Inside, the chassis is screwed into the main case. IBM used aluminium instead of steel to keep the weight down, which is pretty clever really, as it doesn't feel any less rigid.
It does have an impact on the sound, however. The thock is a shallower "thwack" sound compared to the more dense sound the XT's steel assembly has. The pitch of the click is definitely lower on my IBM 5155 keyboards compared to other Models F I've heard. Compared to the other 5155 keyboard, the NOS one is clickier and the thock isn't as pronounced. I don't think the spacebar sounds as good though. Most of the keys also don't ping much, whereas a few keys on the right of the main block do have a noticeable ping. I really like ping, and I find it interesting how it varies so much between models. Why do they all have a different pitch between models? Why are some pingier than others? Is it the springs drying out with use? Is it minor changes in tension? I had a UK Model F XT from 1985 with an extremely pingy spacebar. After a foam replacement and even using the same spring/flipper, the spacebar ping was gone. I also completely ruined the key feel, but that's a story for another time!
Anyway, what do you guys think?