While there are tracker programs that are used for producing 8-bit chiptune tracks (think FamiTracker, SnevenTracker, SnoozeTracker, DefleMask, Raster Music Tracker), most of these programs are not that accessible with a screen reader, or are semi accessible with a bit of patience.
I use most of the programs listed above for producing these tracks, but only because I have a bit of usable vision and thus can use them.
The most accessible way of producing chiptune tracks these days is through MML. Famous in Japan, MML (Music Macro Language) is a music description language used in sequencing music on a number of computer and video game system platforms. It is basically a text file which can be compiled into a native music file from a video game console. So yes, you will have to sequence the music yourself using a text editor like Notepad (I believe there are a ton of resources out there for composing in MML).
As for software, the only pieces of software that are used to process MML data so that it can then be played are:
1. MCK: This program compiles the MML music data, then converts the file into a .NSF (NES Sound Format) file so you can play it back on an NSF player, an emulator, or actual NES hardware.
2. PPMCK: An extension of MCK, this extension adds many features to MCK, one of which lets you switch banks for longer songs (The NES had limited RAM, about 256K).
3. XPMCK: This is an MML compiler which lets you compose music for various video game platforms, including the Amstrad CPC, Capcom Play System hardware, ColecoVision, Commodore 64, Microsoft MSX, Nintendo Game Boy, Sega Master System/Sega Game Gear, and Sega Genesis.
3. HuSIC: A custom version of PPMCK that lets you compose music for the PC Engine/TurboGrafx 16.
4. MuSICA: I don't know much about this one, other than the fact it was made for the MSX.