1979 Heathkit H89 and an ASCII version of Space Invaders. 2MHZ Z80 with 48KB RAM and SSSD Hard Sectored Floppy Drive.
I purchased this from the original owner who built this from kit. It was his first computer and he was very hesitant to let it go – glencanyon.
This has a very basic floppy disk controller, so it can only use hard sectored floppy disks.
These disks hold 100kb of data but since they're hard sectored, they have a very unique sound when loading. While soft sector disks (what we see in the IBM PC) have a single index hold indicating the starting point of sector 1 on each track, hard sector floppy disks have an index hole for every sector.
According to hicooh's comment, Steve Jobs once gave a shout out to HeathKit in an interview. He said that it taught him that products that seem magical and mysterious were all made by regular people just like you, which was a part of what inspired him to make magical and mysterious products of his own.
The READY! MODEL 100 is a portable computer by ready100computer. (Details here.) In case custom keyboards are too mainstream for you. (Sent by Grillsteak28.)